Pirates Player's iPhone Flies Out Of Pocket During Slide In Middle Of Game

Bizarre scene in the Pirates game on Tuesday night -- a player's phone spilled out of his pocket while he was sliding into a bag ... and his manager was pissed about it!

Pittsburgh second baseman Rodolfo Castro committed the blunder in the fourth inning of the Buccos' tilt with the Diamondbacks ... when he went head first into third base.

As the 23-year-old was reaching the bag safely, his iPhone flew from his back pocket ... and hit the base at the same time as he did.

Castro -- who was just called up from the Minor Leagues for Tuesday night's game -- was initially oblivious to it all, but had to pick it up after an ump pointed out to him that it was on the ground. He then handed it over to his third base coach, who didn't appear pleased.

Following the game, which the Pirates ended up losing, manager Derek Shelton was clearly not thrilled with Castro either ... telling media members, "This was just a kid who made a mistake. It’s just one of those things we move forward from and tell him, 'You can’t do that.'"

Castro, meanwhile, said afterward he felt "horrible" about the incident ... and added that it was completely unintentional.

Of course, outside of the unprofessional look of having a phone out during the middle of playing in an MLB game ... the league has become highly sensitive to technology use in the field of play (thanks, Astros).