Speaking at an afternoon press conference, Hoyer took it in stride.
"It's been my mentality this whole off-season training camp, you know, to come out here and act like the starter and be the starter," he said. "And so now that it's official, we can just move on and get ready for St. Louis."
Pettine cited the North Olmsted native's leadership skills and his five years of NFL experience, which included a stint as backup to the Patriots' Tom Brady.
In reaching a decision, Pettine said the coaching staff considered the whole package that Hoyer and Manziel bring - on and off the field.
Both Hoyer and Manziel played poorly in Monday night's pre-season game but Manziel didn't help himself when he was caught on camera flipping the bird to the Washington Redskins.
Hoyer was on a winning streak last season until an October injury knocked him out for the season.