This was supposed to be a routine pick-off attempt. Tampa Bay pitcher Chris Archer tried to get an out for the team while Jose Reyes tried to prevent that with a headfirst dive. Unfortunately, the pick-off throw wasn't on-target and hit the shortstop squarely in the groin.
The rarity of catching a baseball in the groin while diving headfirst isn't the craziest thing about the situation though. Peep how Reyes tries to keep his hand on base while he's in massive pain. That's soldier status. It's a shame the Blue Jays ended up losing the game 4-3 despite his trouble.
Check it out in slow motion below.