The Dallas Cowboys received a major blow in Week 17 after Michael Gallup suffered a knee injury against the Arizona Cardinals. To make matters worse, it could be a significant issue.

Gallup sustained the injury as he scored the Cowboys' first touchdown of the game. Based on the video replays, the 25-year-old wideout seem to have buckles his left knee as he performed an acrobatic catch for the touchdown. He stayed on the field holding his knee in pain before he eventually walked off to the locker room with the help of a team trainer.

The fourth-year wideout was ruled out for the rest of the contest, with the team still evaluating his left knee ACL for any structural damage. The medical staff did a Lachman test on Gallup, which could be a precautionary measure or a hint for a possible ACL injury, via Sports Injury Central.

The Cowboys are certainly hoping for the best for Michael Gallup, especially amid a fairly difficult season for him when it comes to injuries. He missed a huge chunk of the campaign after a calf strain in Week 1, and he only returned in Week 10.

Now, he could be facing another long spell on the sidelines if his injury proved to be serious as feared. If it is any type of ACL injury, there is no doubt his season would end with the playoffs coming and all.