INDIANAPOLIS (AP) — The Colts aren’t sure how much time, if any, rookie quarterback Anthony Richardson might miss after leaving in the first half of Sunday’s 23-16 victory with a right shoulder injury.

Coach Shane Steichen said he didn’t know the extent of the injury immediately following the game. Richardson didn’t speak with reporters and was expected to undergo further evaluation Sunday night.

The rookie was injured on a 4-yard run with 4:29 left in the first half when he fell awkwardly to the ground with two Tennessee Titans draped around him. Richardson stayed down for several minutes before walking slowly to the injury tent, his shoulder noticeably drooping to the right side. After several more minutes in the injury tent, he headed to the locker room with the team’s medical staff.

It’s the third time this season Richardson has been unable to finish a game he started.

“I think when you have a dynamic player like him, and, obviously, one of his skill sets is as a runner, that’s what makes him really good,” Steichen said. “The designed run that he got hurt on, we ran something similar last week that he popped for a big one, and then, obviously, this week, he got the shoulder on that play. So that’s stuff you’ve got to look at.”

NFL scouts were enamored with the unique blend of size, strength and athleticism Richardson displayed earlier this year at the league’s annual scouting combine in Indianapolis.

Indy (3-2) wound up selecting Richardson fourth overall in April’s draft, thinking that with a 6-foot-4, 244-pound frame, he is built to last.

But injuries have threatened to derail Richardson’s promising start.

Since missing the final minute of Indy’s season-opening loss to Jacksonville with minor knee and ankle injuries, he missed nearly three quarters of a Week 2 win at Houston and the Week 3 victory at Baltimore because he was in the concussion protocol.

The former Florida college and prep star returned to action last week, posting his first 200-yard passing game. It also was the first time he started an finished an NFL game.

Now, he’s hurt again.

“Obviously, this is Anthony’s team and it’s going to be his team. I’m very excited for him,” backup Gardner Minshew said after going 11 of 14 with 155 yards in another relief appearance Sunday. “Unfortunately, he keeps having these issues, but he’s playing great, everybody believes in him. I’m grateful for every opportunity I get.”

He could be in line for even more work in the coming weeks.

Fortunately for the Colts, Steichen believes he has the league’s best backup in Minshew, who started against the Ravens and closed out Indy’s other two victories in relief of Richardson.

The rookie was 9 of 12 for 98 yards and ran twice for 5 yards before leaving Sunday.

When he has been healthy, Richardson has played well.

He needs 20 yards rushing to pass Hall of Famer Johnny Unitas for the franchise’s third best single-season rushing total by a rookie quarterback. Unitas had 155 yards in 1956.

Richardson also became the first rookie quarterback in the Super Bowl era to rush for TDs in his first three games. Plus, he already has two games with a TD run and a TD pass, leaving him one short of the Colts’ single-season record held by Unitas, Bert Jones, Peyton Manning and Andrew Luck (three).

The question now is when will Richardson get his next chance?

“I think when something happens like that, you’ve got to fight through those things and that’s part of this league,” Steichen said. “You’ve got to have the conversations that will build you stronger. Sometimes in life with any type of deal, you get nicked up, like why does this happen to me? You’ve got to think about the positives and think that something good is going to come out of it.”