INDIANAPOLIS – When Houston Texans coach Bill O'Brien looks across the field at the Titans sideline this fall, he'll see some familiar faces.

For starters, Tennessee's new head coach, Mike Vrabel, formerly served under him in Houston, including last season as defensive coordinator. Vrabel worked four seasons as an assistant coach under O'Brien with the Texans.

Speaking at the NFL Combine, O'Brien smiled when asked how much advice he's given Vrabel as he embarks on his first season with the Titans.

"He's in the division, so I didn't offer him too much advice," said O'Brien, smiling. "No, he's a very bright guy, very smart, really good coach, good communicator. Every situation's different and I think that, like I said, the type of intellectual ability that he has, his ability to teach and communicate, he's going to do a good job there."

O'Brien also had good things to say about new Titans quarterbacks coach Pat O'Hara, who will work with quarterback Marcus Mariota. O'Brien raved about O'Hara's ability to improve the technique of quarterbacks he's worked with during his career.

O'Hara joined the Titans after spending three seasons (2015-17) with the Texans. In his time with Houston, O'Hara was an offensive assistant who helped coach quarterbacks, including Deshaun Watson. In both 2015 and 2016, the Texans won the AFC South, while posting back-to-back 9-7 records.

O'Hara's playing career spanned 16 years as a quarterback, playing in the NFL, World League and the Arena Football League. Additionally, he spent 10 years coaching in the AFL, including stints as a head coach for the Los Angeles Avengers (2009), Tri-Cities Fever (AF2, 2009), Orlando Predators (2010-11) and New Orleans Voo-Doo (2012-14).

"Pat's a great guy," O'Brien said. "He's very smart, played the position. He played for a long time. He played in the Arena (Football) League, played a little bit in the NFL. He's coached all kinds of different players at that position. He can evaluate that position.

"He's very knowledgeable about the mechanics of a quarterback. I thought that was one of the things he brought to the table for us. He was really knowledgeable about footwork and throwing motion and all those different things, and he's a great friend. Pat's a great friend and he's a really good guy."