INDIANAPOLIS -- Colts quarterback Anthony Richardson has been ruled out of Sunday's game against the Titans with a shoulder injury.

Richardson was finishing off a 4-yard run with 4:39 left in the second quarter when he was tackled by Titans linebacker Harold Landry III. Richardson's right shoulder took the brunt of the impact as he fell to the turf, and he immediately reacted by pointing to his shoulder as he lay on the ground.

He was helped up after being attended to by the team's training staff for a few minutes and was briefly examined in the sideline medical tent before being escorted to the locker room, unable to move his right arm.

Colts tight end Mo Alie-Cox was also ruled out in the second half due to a concussion.

This is just the latest injury concern for the No. 4 overall pick in April's draft. Richardson took a hit to his right knee in the season opener against the Jacksonville Jaguars and was pulled from the game by coach Shane Steichen for the final few plays as a result.

The following week, against the Houston Texans, Richardson sustained a concussion in the second quarter and missed the rest of that game and the following week against the Baltimore Ravens.

Including Sunday's game, Richardson will have played in just 12 of a possible 20 quarters played by the Colts this season.

Gardner Minshew came in to relieve Richardson. Minshew has 25 career starts and was the Colts' starter in their victory over the Ravens in Week 3.