After being placed on injured reserve earlier this week, Indianapolis Colts star quarterback Andrew Luck is out for the year. His 2017 season ended without him taking even a single snap, as he was on the physically unable to perform list throughout the preseason and then spent the first eight weeks of the regular season on the inactive list. 

Luck had surgery on his throwing shoulder last offseason, but the Colts publicly expected that he'd be ready to play. They kept insisting he would be ready at some point, whether it was the start of the regular season, or a few weeks into it, or a few weeks [from whenever the most recent question was asked]. Alas, it never happened. 

Their season spiraled away from them, and then their public statements began to make it sound like Luck would not play at all this season, and then they made that official. And now, not only is Luck shut down for the season, but he's reportedly been advised not to even throw a football for two to three months, and to instead focus solely on rehabilitation. 

According to NFL.com, another surgery is even possible (though unlikely):

Over the past few weeks, Luck sought theories and second opinions from at least four doctors about his surgically repaired shoulder, per sources informed of the situation.

Based on interviews with several people involved in the situation, the picture becomes just a little bit clearer.

First, most recommendations have Luck taking a few months off from throwing -- likely two to three months to focus solely on rehab. At this point, no one has recommended another surgery, though it remains a possibility.

...

The belief is that additional issues arose in Luck's shoulder, which are byproducts of playing through the torn posterior labrum for two years. That, not the labrum, has led to the setbacks.

If surgery was the eventual decision, Dr. Marc Safran of Stanford Medicine would go in and clean up those issues.

But everyone hopes that outcome won't be necessary.

Luck does have several problems inside his shoulder in other parts beyond what was repaired -- most of which came from his mechanics changing due to compensating for the injury. Doctors have tried to figure out if the soreness is from his original issue (they don't think so) or new issues.

Yikes. That does not sound great. Both Luck and the team maintain that the injury is not career-threatening and that he will come back better than ever, but those are not the kind of things you want to hear about your franchise player. As of now, the plan is for Luck to be ready for the start of the 2018 season. But that was also the plan this year, and we saw what happened there.