Tim Tebow's bat has been hot lately ... but, his defense -- not so much, 'cause the ex-NFLer and current Mets farmhand took a ball straight to the dome in a minor league game Monday night!!
It all went down in Portland, Maine in a tilt between Tebow's Binghamton Rumble Ponies and the opposing Portland Sea Dogs ... when Josh Ockimey belted a ball deep to Tebow in left field.
The ball hit high off the wall and came crashing down ... right at Tim's head.
It clanked off his head -- rolled all the way to the fence in foul territory .