CLEVELAND (AP) — Browns third-string quarterback Connor Shaw will undergo surgery on his right thumb and be out for an indefinite period.

Shaw, who started Cleveland’s final game last season as a rookie, injured his thumb during the second half of Thursday’s exhibition opener against Washington. He completed 5 of 10 passes for 64 yards in the 20-17 loss.

The Browns said Shaw will miss “an extended period of time.”

“I feel for Connor because he has worked extremely hard,” coach Mike Pettine said. “He’s a competitor and has had a great offseason and a good camp so far. He is good for the quarterback room and it’s unfortunate that this injury won’t allow him to compete.”

Shaw was listed behind Josh McCown and Johnny Manziel on the team’s depth chart, but the Browns are high on the former South Carolina star, who showed toughness and potential in the 2014 season finale against Baltimore. Filling in for an injured Manziel, Shaw completed 14 of 28 passes for 177 yards against the playoff-bound Ravens. He finished the game despite a dislocated finger and bruised kidney.

The loss of Shaw moves veteran Thad Lewis into Cleveland’s No. 3 quarterback role. The Browns also have Terrelle Pryor, who is trying to make the switch from quarterback to wide receiver. The Browns have no immediate plans to sign another quarterback.

Following Sunday’s walk-through practice, the team is taking a train to Rochester, New York, for two days of practice against the Buffalo Bills at St. John Fisher College. The teams will then play an exhibition game on Thursday night in Cleveland.

The Browns also signed cornerback Aaron Ross and linebacker Everette Brown.

A former first-round pick by the New York Giants, Ross missed last season with Baltimore due to an Achilles injury. He has appeared in 83 career NFL games and won Super Bowl titles with the Giants in 2007 and 2011.

The 6-foot-3, 263-pound Brown has played six seasons as a pro. He appeared in six games for Washington last season and has been with Carolina, San Diego and Dallas.