The Indianapolis Colts have placed Anthony Richardson on injured reserve and the rookie quarterback will miss at least four games. Richardson suffered an AC joint injury to his right shoulder during the second quarter of Sunday's victory over the Tennessee Titans.

According to ESPN's Adam Schefter, Richardson's absence could extend anywhere between four and eight weeks depending on the amount of rehab he will need or if the shoulder will need surgery.

Richardson's injury means he will miss at least the Colts' games against the Jacksonville Jaguars, Cleveland Browns, New Orleans Saints, and Carolina Panthers. The earliest he could return is for the team's Week 10 matchup against the New England Patriots in Frankfurt, Germany.

Through four games, Richardson has 577 passing yards, a 59.5 completion percentage and seven passing and rushing touchdowns.

The Colts will now turn to Gardner Minshew for Sunday's game in Jacksonville. The veteran quarterback went 11-for-14 with 155 passing yards after Richardson left the game.

"It's tough when a guy gets dinged up like [Richardson's] been dinged up," said Colts head coach Shane Steichen on Monday. "He's obviously a very, very talented player, and it's tough. But we have a lot of faith in Gardner, too, to step in and go operate the way he's been doing."

With Richardson on injured reserve and Minshew getting elevated to the starting job, the Colts signed quarterback Kellen Mond to their practice squad with Sam Ehlinger now serving as backup.

This is the third time injury has kept Richardson off the field during his rookie season. He left the season opener in the fourth quarter with a knee injury and suffered a concussion the following week, which caused him to miss their Week 3 win over the Baltimore Ravens. Minshew stepped in and went 27-for-44 with 227 passing yards and one touchdown pass against Baltimore.

The winner of Sunday's game between the Colts and Jaguars will take over first place in the AFC South division.