He's about to take the field with the bigger boys.
Manziel, who in his coach's estimation had a "positive" rookie minicamp, will practice this week with the club's veteran players, including Brian Hoyer, the quarterback he'll try to unseat as the starter.
First-year coach Mike Pettine made it clear that Manziel and Hoyer realize what's at stake and that their competitive juices are already flowing.
"I don't know if they're going to be sending each other Christmas cards anytime soon," Pettine said. "But they both know they're in it together and they're going to compete. I think they both feel comfortable that, as a staff, we're going to put the best quarterback that puts us in position to win games, we're going to put him out there."
The coach spoke Monday after appearing with Cleveland Indians manager Terry Francona at a Positive Coaching Alliance breakfast at FirstEnergy Stadium.
Pettine reported that Manziel, the uber-hyped former Texas A&M star, succeeded in every aspect of the three-day camp, which was open to the media for only 15 minutes on Saturday as the team tries to curtail "Manziel-mania."
"It was a good start for him," Pettine said. "We weren't that concerned about the execution of plays. It was very difficult with a pieced-together offensive line and receiving corps guys who were learning the offense, too. It was a little ragged across the board when you're bringing in guys and it's new to all of them. I thought he did a good job handling himself in the huddle and making the call and the pre-snap communication, knowing where to go with the ball.
"It was a good learning process for him. I think it was a positive thing."
Pettine limited media access to local reporters and photographers. He wants to minimize distractions for his younger players, who might get caught up in the hoopla surrounding Manziel.
"We know the fire is burning, we just don't want to throw gas on it," he said.
Manziel may have a larger-than-life persona and celebrity friends, but Pettine said he came across as grounded and humble around his teammates.
"They see Johnny in the locker room, and they know he's a good guy and a good teammate," Pettine said. "There's no diva-type personality there -- he's just another guy. He's funny and fun to be around, and he's going to work hard, and that's something they all respect."
Hoyer, who is coming off right knee surgery after being injured in his third start last season, might be allowed to do more in this week's camp than he did during last month's voluntary workouts. Hoyer was limited then to 7-on-7 passing drills.
"The biggest problem is not the structure of the knee itself, but more somebody running into him," Pettine said. "He's cleared to do everything, but we just kept him out of team work because we didn't want other bodies flying around him. So we might try to simulate 11-on-11 with him in there."
It's going to be tough to keep Hoyer off the field.
After the Browns traded up and drafted Manziel with the No. 22 overall pick, Hoyer told the team that he was up for the challenge and intended to beat out college football's biggest star.
Pettine said those are words a coach likes to hear.
"That's the way you want it," he said. "He's an ultra-competitive guy. He knew that more than likely we were going to bring in a quarterback, and he reacted the way we want him to react, which was 'Bring it on, let's go.'"