Colts QB Anthony Richardson undergoes season-ending shoulder surgery

Indianapolis Colts rookie quarterback Anthony Richardson had season-ending surgery on his throwing shoulder Tuesday, team owner Jim Irsay said in a social-media post.

Irsay wrote that the lengthy procedure took place in Los Angeles and doctors found what they expected. He said Richardson is doing well and that there is no scheduled date for his return to Indy, where he now lives.

"No new surprises were found during surgery — they just repaired what was expected. Anthony is doing well and thanks everyone for the support," Irsay wrote.

The Colts drafted Richardson out of Florida with the fourth overall pick.

He made four promising starts but only finished one game because of a variety of injuries. A bruised knee and sore ankle forced him to sit out the final minute of Indy's season opener, and he was knocked out of a Week 2 win at Houston when he entered the concussion protocol. He didn't play in Week 3 and then went to the ground awkwardly in Week 6, resulting in a sprained AC joint in his right shoulder.

Initially, the Colts (3-4) put Richardson on injured reserve. The team and Richardson agreed last week that surgery was the best option.

Gardner Minshew has replaced Richardson as the starter. He's appeared in all three of the Colts' wins, including a start in the Week 3 win at Baltimore. But since Richardson went down, Minshew has thrown four interceptions, lost four fumbles and been sacked seven times in two straight losses.

The latest loss — to Cleveland last Sunday — included back-to-back questionable calls against cornerback Darrell Baker Jr. with the first erasing what would likely have been a game-sealing turnover and the second moving the ball to the 1-yard line.

"The NFL admits and understands that they did not make the correct calls at end of Sunday's Colts/Browns Game," Irsay also wrote. "I believe we need to institute Instant Replay for all calls, including Penalties, in the last two minutes of All Games."

Reporting by The Associated Press.