INDIANAPOLIS (AP)The Indianapolis Colts know one thing about Anthony Richardson’s shoulder injury: It will keep him out of next weekend’s game at Jacksonville.

Everything else remains unclear.

One day after the rookie quarterback injured the AC joint in his right shoulder on an awkward 4-yard run against Tennessee, coach Shane Steichen announced Gardner Minshew would make his second start of the season, this time against his former team.

“It’s tough,” Steichen said, referring to the latest injury. “You know a guy gets dinged up like he gets dinged up and he’s, obviously, a very talented player and it’s tough. But you know we’ve got a lot of faith in Gardner to step in and go operate the way he has been.”

Minshew is getting used to being the quarterback on call.

He’s won three of the four Colts games he’s appeared in, two in relief of the injured Richardson, while completing nearly 69% of his throws without an interception. He spent his first two NFL seasons with the Jaguars (3-2).

The bigger concern in Indy (3-2) is Richardson’s long-term health.

He missed the final minute of his pro debut, a loss to the Jaguars, with a bruised knee and sore ankle. He entered the concussion protocol during the first half of a Week 2 win at Houston before sitting out a Week 3 overtime victory at Baltimore while still in the protocol.

Now it’s his throwing shoulder. Steichen said the Colts still collecting medical information before providing a timetable or talking about treatment options.

“We’re still evaluating all that stuff and once we get more information on it, we’ll let you know,” he said when asked whether a trip to injured reserve or surgery were possible.

Richardson would miss at least four weeks if he goes on injured reserve.

Indy selected Richardson with the No. 4 overall pick in April’s draft following his performance at the league’s annual scouting combine. And though some considered the former Florida prep star and Gators star a project after starting only 13 college games, Richardson has made a relatively smooth transition to the NFL.

Though his completion rate (59.7%) needs improvement, he’s thrown for 577 yards, three TDs and has just one interception. He’s also run 25 times for 136 yards and four scores, becoming the first quarterback of the Super Bowl era with TD runs in each of his first three NFL games.

If Richardson does return this season, he will be chasing the single-season franchise record for most games with a TD pass and a TD run as well as the Colts’ rushing record for a rookie quarterback.

To do that, though, he must get healthy – and stay healthy.

Jags quarterback Trevor Lawrence advised Richardson to take care of himself after the two met in Week 1. Since then, the 6-foot-4, 244-pound Richardson has been cheered by Colts fans when he runs out of bounds or slides.

But Steichen doesn’t want to completely remake Richardson’s game.

“His ability to do what he does and be a dynamic runner is, obviously, a big part of his game,” Steichen said. “He’s had some huge runs in games, he’s made some big plays and, obviously, you never want injuries to happen. I know it’s part of the game, but we’ve got to just keep evaluating that stuff and continue to be smart with him.”