NASHVILLE – Marcus Mariota got the news he didn't want to hear.
But the Titans quarterback on Wednesday vowed to be the best teammate he can be as he transitions into an unfamiliar role – as a back-up, behind new starter Ryan Tannehill.
"It is going to be different," Mariota said. "I haven't really been in this role for a long time, really at all in my career. But I am going to do everything I can to help Ryan and help this team. Ryan was supportive of me, and this is my opportunity to just be a good teammate."
Titans coach Mike Vrabel announced on Wednesday that Tannehill will be the starter for Sunday's game against the Chargers.
Tannehill replaced Mariota in the third quarter of Sunday's game against the Broncos, an eventual 16-0 loss. It was Tannehill's first action since the Titans traded for the former Dolphins starter back in March.
Mariota completed 7-of-18 passes for 63 yards and two interceptions and a 9.5 rating against the Broncos before being replaced with 4:49 in the third quarter. On the season, Mariota has completed 94-of-159 passes for 1,179 yards with seven touchdowns and two interceptions, with a 91.7 rating. He's been sacked 25 times in six games, however, and the team has been held to a touchdown or less in three of its first six games.
In making the decision, Vrabel said the team wanted to "get a little spark."
"I am very confident, after having talked to Marcus and watching him prepare already today that if called upon, at some point and time, we expect him to be ready to go," Vrabel said. "It is not an easy thing for any player. I would say it is not an easy thing for a coach that cares about his players … to make that decision.
"But we felt like this was the right thing for the team right now."
Mariota, the second overall pick of the 2015 NFL Draft, said he'll continue to work to be ready if needed.
"I think it is an opportunity for me to learn, and I am going to make the most of it," Mariota said. "No matter what, each and every single day I am going to approach it with the mindset to learn. You have to be ready at any point and time. No matter what, I will prepare just as I have, and I'll be ready to roll."
Mariota said he's determined to be successful moving forward.
"It's a tough pill to swallow, but for me as an athlete I can learn and grow," he said. "For me, my expectation is to be the best player I can be. To the day that I die, I'll believe that I gave it all I've got. No matter what I can learn and grow from this situation. This isn't going to bring me down, this isn't going to end my career. This is an opportunity for me to grow and I'm going to make the most of it."
The Tennessee Titans practice on Wednesday, Oct. 16, 2019 at Saint Thomas Sports Park. (Photos: Donald Page)
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/ynuszx2h8btjglixofwu.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/vbyubkzacztyhylpxsao.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/nvuz0blo69zbnctnktzn.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive back Amani Hooker #37 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/edkgi305gol03be6bg41.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive back Amani Hooker #37 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/dc9lfqjlj9frs1l7ncmq.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/rr5zhesr1j6acda3bksx.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Tight end Jonnu Smith #81 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/asd9xrmxtha0sz08csgb.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Tight end Jonnu Smith #81 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Tight end Jonnu Smith #81 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/osnhe7plthztto7bwxjn.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Tight end Jonnu Smith #81 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Tight end MyCole Pruitt #85 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/mgmoopoywc5nnosb2y6o.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Tight end MyCole Pruitt #85 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/pbcpnwavpkewrsldt34z.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Austin Johnson #94 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/fhpkhdgqk95457apqeos.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Austin Johnson #94 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/jhiympgsocqc4eqmpa5y.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive tackle Isaiah Mack #97 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/nik01terkk7dx1brgjsd.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive tackle Isaiah Mack #97 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive tackle Isaiah Mack #97 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/jnj1ad6mmheqzr70ylri.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive tackle Isaiah Mack #97 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/hwjktlmwlbmpgrqqioq4.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive end Matt Dickerson #92 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Austin Johnson #94 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/djaozryrp9l7szpcn35v.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Austin Johnson #94 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Wide receiver Tajaé Sharpe #19 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/nvhksudp3tdcvc7ud6rh.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Wide receiver Tajaé Sharpe #19 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/fytgvxtvwx3mqkhpzzzt.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive lineman Jeffery Simmons #98 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Running back Derrick Henry #22 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/pbuwrtmbbeku6cu5s9qz.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Running back Derrick Henry #22 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Wide receiver Tajaé Sharpe #19 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/com2myutsx5eljibqfmp.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Wide receiver Tajaé Sharpe #19 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans
![NASHVILLE, TN - OCTOBER 16, 2019 - Defensive back Dane Cruikshank #29 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans](https://static.clubs.nfl.com/image/private/t_new_photo_album/t_lazy/f_auto/titans/nwukvzte3m5a5l9yeezd.jpg)
NASHVILLE, TN - OCTOBER 16, 2019 - Defensive back Dane Cruikshank #29 of the Tennessee Titans during practice at Saint Thomas Sports Park in Nashville, TN. Photo By Donald Page/Tennessee Titans