Alex Rodriguez may have already hit career home run #500, though according to his stats, he stands at #499. It all depends on whether he hits #493 tonight.
MLB.com explains that if Slappy homers tonight -- when the Yankees finish their June 28 suspended game at Baltimore -- it would go into the record books as having happened on June 28.
Thus, his 500th chronological career home run would be backdated to #493 (he had 492 coming into June 28) and the seven home runs he has hit since June 28 would be bumped up, making #499 -- which Slappy hit off Kansas City's Gil Meche on Wednesday -- the "official" #500.
The June 28 game was suspended in the top of the eighth inning, with New York up 8-6 and Rodriguez on deck.