**
NASHVILLE, Tenn. —** The Titans have one more running back on their roster -- and one less quarterback.
On Wednesday morning, the team activated running back David Cobb from "Injured Reserve-Designated to Return." A fifth round pick by the Titans in the 2015 NFL Draft, Cobb joins a stable of running backs that also includes Antonio Andrews, Dexter McCluster, Bishop Sankey and fullback Jalston Fowler.
Cobb was placed on Injured Reserve prior to the start of the season because of a calf injury. He began practicing with the team last month, and the Titans were required to make a decision on him this week. Cobb should provide a boost to a running game that's relied heavily on Andrews in recent weeks.
To make room on the roster for Cobb, the Titans waived quarterback Charlie Whitehurst.
Whitehurst, a 10-year NFL veteran, served as the No.3 quarterback behind quarterbacks Marcus Mariota and Zach Mettenberger this season, but he was inactive for six of the team's first eight games. Whitehurst was active for two weeks when Mariota was out with a knee injury, but he didn't play.
Whitehurst started five games for the Titans in 2014, and played in seven games. He completed 105-of-185 passes for 1,326 yards and seven touchdowns, with only two interceptions.
In addition to those moves on the 53-man roster, the Titans also added outside linebacker J.R. Tavai and tight end Kevin Greene to their practice squad.
Tavai (6-2, 249) originally signed with the Titans as an undrafted free agent this past spring. He was injured in the first preseason game against Atlanta, however, and placed on injured reserve at final cuts. The Titans agreed to an injury settlement with Tavai shortly after being placed on injured reserve and he is now eligible to re-sign with the team. He was a two-year starter at the University of Southern California.
Greene (6-3, 242) entered the NFL as an undrafted free agent with the San Francisco 49ers following the 2014 NFL Draft. He spent time on the practice squad with both the Cincinnati Bengals and Carolina Panthers last season and went through training camp this year with the Chicago Bears. Greene was a linebacker/defensive end for the majority of his college career at the University of Southern California, before moving to tight end as a senior.
Titans Online looks at the collegiate career of Minnesota RB David Cobb. (AP Photos)
