Sandy Alcantara is headed to the Injured List. The reigning Cy Young winner in the National League is set to spend some time on the shelf now. The pitcher had not been quite as effective this year as last year, but he was still a vital piece in what is a surprising playoff push for the team.
The injury in question is a right forearm flexor strain. That is usually not a good sign as it can be troublesome to recover from and it can be an indicator of a worse injury.

The Marlins have seen the emergence of Jesus Luzardo and Eury Perez to offset the step back for Sandy Alcantara, who has still been a solid pitcher for them this season. Now, they will be without him for a while.
It's a brutal blow to endure during the middle of a playoff push. The Marlins are currently a half game back of the third Wild Card, the pursual of which will now fall to the rest of the starting rotation.
The timing of this could have been better as well for the Marlins. The pitcher is heading to the shelf with one month remaining in the season. Not only is it crucial time for the playoffs, but it also leaves open the possibility of a season-ending injury.
Sandy Alcantara headed to the IL
Sandy Alcantara reportedly experienced some issues after his last start, citing some discomfort in his arm. That's never a good thing, and it turned out to be bad this time around.

There are still tests being done on the pitcher's arm, but it doesn't look good for a return this year. This usually requires three weeks of rest and then some rehabilitation, which means at best, a return for the hypothetical playoffs could occur.
He had pitched to the tune of a 4.14 ERA (down from earlier in the season) and 2.8 fWAR before the injury.