The New England Patriots' mandatory minicamp on Tuesday was pretty quiet as a total of 13 of their players didn't show up. One of them is Rob Gronkowski, who is suspected to be suffering from a new injury.

The tight end has been a powerful factor for the Patriots which is why his absence from the minicamp is causing quite a stir. According to various sources, he might be injured, which could also endanger his participation in next season's games.

It's also not comforting that Gronkowski has a bit of a history when it comes to injuries. Back in 2012 and 2013, he missed a few games with the Patriots due to a serious back injury. His other season in the NFL weren't spotless either since during his entire game in the league, he was only able to play complete seasons twice.

During the 2015 season, Gronkowski got an injury that looked pretty severe during the Patriots' game against the Denver Broncos. During the fourth quarter of that match, he suffered a knee injury and had to be carried off the field using a cart.

But, as noted by the Boston Herald, Gronkowski may not be suffering from a serious injury after all. According to the news site's source, the Patriots are being careful with the athlete this offseason. Specifically, they're avoiding to work him out t0o much to avoid the risk of another injury that could jeopardize his 2016 season with the team.

Also, even though he did not show up at the minicamp, the site stated that Gronkowski was on the premises but is currently dealing with an ailment. Although the nature of the condition was not disclosed, the source noted that it's not major and does not endanger the athlete's playing capabilities.

On the other hand, Bill Belichick, the head coach of the Patriots, was a bit coy when asked about the whereabouts and condition of Gronkowski and the other players who didn't participate in the minicamp.

"There are a lot of players that were not on the field," he simply said according to ESPN. "They were doing other things."