Embattled Cleveland Browns quarterback
After a rocky rookie campaign that saw Manziel briefly take over -- and lose -- the Browns' starting quarterback job, Browns offensive tackle
"I think he's going to have to prove to the team that football is important," Thomas told ESPNCleveland.com "and being the man, being the starting quarterback for the Cleveland Browns, is important, it is his goal, his single goal in his life."
Manziel has been in rehab for more than two months, but Browns General Manager Ray Farmer expressed confidence he would be out in time to take part in team workouts, which are scheduled to begin April 20. Thomas is hopeful Manziel will approach the team with a different mind set once he leaves treatment.
"You know, I think he lost probably a lot of trust among the guys on the team last year by the way he handled himself once he became the starter," Thomas said. "And I think he had a lot of time to reflect, I'm guessing, after the season was over by the comments he made in the media and by his actions, checking himself into rehab... I think those were really positive steps.
"I'm hoping when we come back in April we see a new Johnny and everybody's blown away with his commitment," Thomas continued. "And I think he's got the talent, so it's just a matter of if he commits himself to it, we can have a really good quarterback on our hands."
Manziel, who entered rehab on Jan. 28, has been criticized for his partying lifestyle reputation. In the past, he has posted photos of himself on Twitter and Instagram drinking at parties.
A star quarterback at Texas A&M who was drafted 22nd overall by the Browns in 2014, Manziel appeared in five games for the Browns last season, passing for 175 yards.