Offseason developments:** Marcus Mariota added five pounds to his 6-foot-4 frame, and is now closer to 225 pounds. He's looked stronger, and more confident. The Titans signed veteran Matt Cassel in March after releasing Zach Mettenberger, who started 10 games over the past two seasons. Cassel has won games in the NFL, and he's been a good sounding board for Mariota this offseason. Mettenberger was claimed by the Chargers, where he was reunited with former Titans coach Ken Whisenhunt, now offensive coordinator in San Diego. Alex Tanney returned to compete for the No.3 spot in Tennessee, and he's had a solid offseason.

In the spotlight: Mariota. Of course it has to be the starter. Mariota set franchise records for most touchdowns (19), completions (230), passing yards (2,818) and passing attempts (370) in his first NFL season despite missing four games with knee injuries. The Titans have been pleased with his progress, but cleaning up things at the line of scrimmage and being more accurate throwing the deep ball are among the things on his preseason checklist. So far, he's looked very comfortable while working with new offensive coordinator Terry Robiskie. With more weapons around him, there's reason to believe he'll make a big jump in 2016.