Browns third-string quarterback Thaddeus Lewis took reps with the starters today because rookie Brandon Weeden (sprained throwing shoulder) and Colt McCoy (sore throwing shoulder) did not practice today.

If neither Weeden nor McCoy can play Sunday, Lewis would start for the Browns (5-10) in their season finale against the Pittsburgh Steelers (7-8) at Heinz Field. Lewis, who has spent the majority of the past two seasons with the Browns as a member of their active roster and practice squad, has never played in an NFL regular-season game.

“Whoever’s in there I trust,” Browns coach Pat Shurmur said today. “I’ve had experience with Thad in the past, and he hasn’t had a lot of opportunity in regular-season games to go in there and play. But if he’s in there playing, we definitely trust that he’ll do a good job.”

The Browns signed former Tampa Bay Buccaneers quarterback Josh Johnson to their active roster today, and he would serve as Lewis’ backup if Weeden and McCoy are sidelined. Johnson ran the scout team today in practice, Shurmur said.

Weeden sprained his right shoulder Sunday in the third quarter of the Browns’ 34-12 loss to the Denver Broncos. McCoy’s right shoulder is sore, too, because he hurt it against the Broncos, Shurmur said.

“[McCoy] told us he was sore and came in and got treatment,” Shurmur said.

Neither Weeden nor McCoy have been ruled out, Shurmur said.

In addition to Weeden and McCoy suffering injuries against the Broncos, rookie running back Trent Richardson hurt his left ankle when McCoy fell on it during the Browns’ second-to-last offensive play Sunday.

Weeden and Richardson will not need surgery, Shurmur said. Shurmur has not ruled Richardson out, either.

“Their injuries will not require surgery,” Shurmur said. “They’ll be healthy soon. They won’t practice today, but I will not rule them out for this weekend. We’ll see as the week goes on.

“The injuries were not as severe as you might have thought. But they’re still injured.

“If they’re healthy and they’re willing and they’re able to go, then, of course, they’ll play. We’ll make that decision go. If think you’ve got to overlook the fact that it’s your last game and try to make your decisions based on playing this next game. If they’re able to go, they will. If they can’t, then I don’t have any problem here at the end of the week ruling them out before Sunday. But we’ll see.”

Another roster move

To make room for Johnson, a fifth-round draft pick in 2008, the Browns placed safety Usama Young on injured reserve with a thumb injury that will likely require surgery. Young started 11 of the 13 games in which he appeared this season. He compiled 52 tackles, including 1.5 sacks, three interceptions, seven passes defensed and a fumble recovery.

Undrafted rookie safety Tashaun Gipson practiced today after sitting out against the Broncos with an injured foot. Gipson and Eric Hagg can either play strong safety or free safety, Shurmur said. Both of them are expected to start.

Extra points

Shurmur said cornerback Sheldon Brown "is coming back from a concussion, so time will tell" regarding his availability. Brown and tight end Jordan Cameron (head) did not practice today along with Weeden, McCoy and Richardson. ... Defensive end Jabaal Sheard will serve as the Browns’ fourth captain against the Steelers. … The Browns signed safety Jordan Mabin, a graduate of Nordonia High School, to their practice squad. … The AFC and NFC Pro Bowl rosters will be announced at 7 p.m. today. Shurmur said Browns kicker Phil Dawson is among the players he’s hoping make it.