"He was the clear leader from the beginning," coach Mike Pettine said in a statement. "We've maintained all along that if it was close, I would prefer to go with the more experienced player. Brian has done a great job in the meeting rooms and with his teammates on the practice field and in the locker room."
Hoyer started Monday's preseason game against the Washington Redskins, completing two of six passes for 16 yards. Manziel, the No. 22 pick in the draft, completed seven of 16 passes for 65 yards and a touchdown in the Browns' 24-23 loss.
The move comes on the heels of Manziel being caught on camera during the game making a middle-finger gesture toward the Washington bench.
"That type of behavior is unacceptable," Pettine said Tuesday. "He should know more than anyone that all eyes are on him."
Hoyer started training camp as the starter and though he admitted he did not play well in Washington, he never really did anything to lose the job. Combined with the reality that Manziel didn't take it away, Hoyer will be the starter for Week 1 against the Pittsburgh Steelers.
"I think Brian's been very poised," Pettine said Wednesday. "I think he's handled the situation well. He's had a lot of things going on.
"I think it's especially good, as an offensive unit, to go out and play and gain cohesion and chemistry. That was one of the reasons I wanted to go ahead and make the decision before this third preseason game so that (Hoyer and the rest of the starting offense) could play as a unit for a good chunk of it."
The decision means Hoyer has a little more time to hang onto his dream of starting for his hometown team. Hoyer grew up in suburban North Olmsted, and attended St. Ignatius High School, where he played for legendary Cleveland coach Chuck Kyle.
Hoyer has only four starts in his career -- three last season with the Browns, one that lasted less than five minutes before he suffered a torn ACL on Oct. 3 against the Bills.
"I think a lot of people discount that," Pettine said. "Here's a guy coming off of a season-ending knee injury. Really, these are his first, essentially, 20-25 plays of live work back from it, and he's only going to get better."
Before the injury Hoyer led the Browns to two wins in his previous two starts -- rare air for a Cleveland quarterback the past six seasons.
He guided a game-winning drive in Minnesota, a game in which he threw three interceptions and three touchdowns, then came back to guide the Browns to a win over Cincinnati, a game in which he threw two touchdowns and no interceptions.
Hoyer has 18 games of experience in his five seasons, but gained his most valuable exposure while learning in New England behind Tom Brady. That taught him the value of preparation and making quick decisions, both of which are his strengths and both of which will be essential against a team like the Steelers.
Pettine said the move does not reflect poorly on Manziel's performance this preseason.
"He's certainly made great strides," Pettine said of Manziel. "We are pleased with where he is, and he has shown that he has come a long way in his ability to pick up the playbook, be coachable and lead an offense. We are confident that Johnny is going to have a great future, but we just felt that Brian still had a decided edge on him."
Only once since the team returned to the NFL in 1999 has a Browns quarterback started all 16 games in a season. That was Tim Couch, in 2001.