Colts QB Anthony Richardson suffers Grade 3 AC joint sprain, to miss one month or more

Unfortunate news in Indianapolis.

Colts starting quarterback Anthony Richardson received an initial diagnosis of a Grade 3 AC joint sprain that will keep him out for a month or more, NFL Network Insider Ian Rapoport reported on Monday.

On Sunday, Richardson suffered a right shoulder injury in the second quarter against the Tennessee Titans. The rookie QB did not return to the field, and it was initially reported that it was, in fact, an AC joint sprain. Other than that, X-rays came back negative, Rapoport reported Sunday.

However, he will have an MRI on Monday morning to confirm the news and reveal the severity of the injury, Rapoport reported.

This is just another injury to add to the list for Richardson. In Week 1 against the Jacksonville Jaguars, the 21-year-old was dealing with knee soreness toward the end of the game. Then he was ruled out in Week 2 against the Houston Texans due to a concussion and also missed Week 3 against the Ravens for the same reason.

The rookie has shown real promise so far this season, completing 41-of-72 passes while throwing for 479 yards, three touchdowns and one interception.

However, backup QB Gardner Minshew will most likely be the one under center for the Colts' Week 6 matchup against the Jaguars, and for the time being. Minshew has been reliable for Indianapolis. When the 27-year-old started for the Colts in Week 3, he brought home a big win, completing 27 of 44 passes, throwing for 227 yards and one touchdown.

On Sunday, Minshew also led the Colts to another victory against the Titans. Now, with Richardson sidelined for quite some time, Minshew will have to keep it up.