Johnny Manziel is honest when he's asked about how he felt when the Browns went back to Josh McCown as the starting quarterback after Manziel led Cleveland to its first win of the season.

"It was a little bit disheartening," Manziel said after Sunday's 24-6 loss to St. Louis.

Still, Manziel's understanding of the decision was firm. He watched McCown have one of the best three-game stretches for a Cleveland Browns quarterback in franchise history and saw the Browns come just a few first downs away from upsetting the Denver Broncos in Week 6.

The second-year quarterback believes he got better watching McCown from the sidelines over the past month. It's why he's confident he'd be ready for the challenge of the Arizona Cardinals on Sunday if McCown is unable to play because of a shoulder injury.

"I've learned a lot from the position I've been in these past couple weeks with Josh being there," Manziel said. "I think my football knowledge and football IQ has gone up more this season, more being with this staff and being with Josh, especially with having Austin (Davis) in the room as well. It's a really smart quarterback room with Kevin O'Connell in there.

"Even though I'm not playing, even though it's disappointing, I'm continuing to learn more and more about this game and more and more about the position I didn't know in the years past. That's all you can ask in the role I'm in."

Manziel relieved McCown with a little more than 5 minutes to play Sunday. He completed 4-of-5 passes for 27 yards.

Browns coach Mike Pettine said Manziel would start in place of McCown if McCown was unable to play because Manziel is the team's No. 2 quarterback. The players who spoke after Sunday's game unanimously said they'd be ready and prepared to succeed with Manziel at quarterback if that's what happened.

"This is a team game so everybody has to pull it together," running back Robert Turbin said. "Josh can't have any success without any of us out there blocking, routes, receiving. It's the same thing with Johnny back there as well. Johnny is going to work hard, prepare if he has to start next week. He'll be ready to go and so will the other 10 guys on the field."

Last week, Pettine said Manziel's improvement as a quarterback and as an all-around player inside the building has been "extremely positive" but expressed disappointment with an off-the-field incident that made headlines leading up to the Browns-Broncos game.

Manziel said he found "solace" inside the Browns training facility and would cooperate with any potential NFL investigation.

"I'm trying to do the right things on the field," Manziel said. "I'm trying to keep my head down and keep plugging and keep pushing and keep trying to gain back what I felt I lost last year in a rough rookie season. That's what I'm doing right now, just keeping my head down and continuing to plug and continuing to learn and making the most of my opportunities when I get in there."