ST. LOUIS -- Another week, and more uncertainty for the Cleveland Browns at quarterback.

Josh McCown left the Browns' 24-6 loss to St. Louis late with a shoulder injury on Sunday, and Johnny Manziel took over with 3:26 left.

On McCown's last play, he was hit from behind as he threw. After he went to the sideline, he did not use his right arm at all.

Head coach Mike Pettine didn't know the severity of McCown’s injury and said the quarterback will be further evaluated Monday.

“Any time you have a player get evaluated for an injury, it’s obviously a concern,” Pettine said. “Whatever the circumstances are, we’ll deal with them appropriately.”

As McCown walked in the locker room, he held his right arm at his waist. Based on that visual, it seems reasonable to assume Manziel could start the Browns' next game against Arizona.

What it means: The culture of losing that has permeated the Browns organization has not gone away. After starting his first season with a 7-4 record, Pettine has lost 10 of 12 games. The Browns continually find ways to lose. Issues they thought they had addressed are still there, especially in the run defense and run game, and issues they did not address, such as finding a dependable big receiver, are glaring. Losing teams find ways to lose. The Browns have had years of practice at mastering that art since 1999.

A reason to worry: The Browns did themselves in with their own mistakes, and there were many in this loss. Turnovers gave the Rams their first 10 points. Another fumble in the fourth quarter led to another Rams touchdown. A holding penalty on Joe Thomas wiped out a lovely catch by Travis Benjamin that would have put the Browns at the St. Louis 21, down four points. A holding penalty on K'Waun Williams gave the Rams a key first down before a Todd Gurley touchdown run. A pass-interference penalty on Pierre Desir preceded a deep connection to Kenny Britt -- who beat Desir and set up a touchdown. The list goes on. The Browns finished the game with 11 penalties and four turnovers, and went 3-for-12 on third down. Those are not the numbers of winning teams.

What were they thinking? The one player the Browns badly need is a tall target in the red zone. That guy was supposed to be Dwayne Bowe, and GM Ray Farmer relied on his past association with Bowe to sign him and give him $9 million in guaranteed money. Clearly Pettine does not share the same feelings about Bowe. Pettine has had him inactive the past three games, and five of seven this season. He’s been healthy the past three weeks. Why sign Bowe if he wasn't going to play?

Losing the ball: Quarterback fumbles have been a huge issue all season. When McCown lost a first-quarter fumble, it gave the Rams a field goal. That was McCown’s fifth fumble this season, four of them lost. (He added a sixth later in the game.) Add Manziel’s four fumbles, and Browns quarterbacks have put the ball on the ground nine times this season.

On the money: Travis Coons was an unknown first-year kicker when the season began. He now has made 14 field goals in a row to start the season.

What’s next: The Browns return home to play the Arizona Cardinals' powerful offense in a 1 p.m. game.