Former Indianapolis Colts quarterback Andrew Luck shocked the NFL world on Saturday when he announced his retirement. This came as a complete surprise, as Luck was about to enter his prime at age 29. In a somewhat similar move, former New England Patriots tight end Rob Gronkowski announced his retirement at the beginning of this offseason.

But on ESPN's Get Up, former NFL player Keyshawn Johnson believes that neither of these retirements are for good.

If either Luck or Gronkowski comes out of retirement, it wouldn't be a huge surprise.

Both are young enough to return, and certainly skilled enough. Luck retired as one of the best quarterbacks in the NFL, and seemed poised to lead the Colts on a playoff run this season. But the former number one overall pick dealt with a plethora of injuries during his time in the league, forcing him to miss the entire 2017 season and potentially the start of 2019, too. Luck said that the constant cycle of injuries and grueling rehab affected his mental health. But if he gets healthy in both his body and mind, it wouldn't be a shock to see him return.

While it's a given that Luck will miss at least a couple seasons, there has been speculation that Gronkowski will return at some point in 2019. This is a little far fetched, but a comeback is definitely a possibility for Gronk. He's another player whose career was derailed by injuries, but if his health improves, it would come as no surprise to see him back on the field.