Joe "Big Irish" Mahoney made his Orioles debut in Saturday's game against the Angels, on July 7, 2012. He went 0-3 at the plate but fielded all seven of his chances cleanly at first base.
Joe was the organization's minor league player of the year in 2010 and was added to the 40-man roster following that season. He finally cracked the big league roster last Thursday, but it was beginning to look like he might not make it into a game, as had just happened with pitcher Steve Johnson who had spent three games with the team but wasn't needed due to solid pitching performances before being sent back down.
But then Joe's name appeared in the lineup for Saturday's game and he officially became Oriole #930. I wouldn't be surprised if he is sent back down to AAA Norfolk shortly after the All-Star break for more seasoning, as I have read that his call-up had more to do with his already being on the 40-man roster than the team needing yet another first baseman on the roster.
UPDATE- The Orioles just sent Mahoney back to Norfolk to make room for Nick Markakis's return from the DL. So it looks like my prediction was correct, if not the timing of the transaction.
As you can see, I have a number of Joe's autographs in my collection, mainly from his time spent with the Frederick Keys and Bowie Baysox from 2009-2011. Outside of the two orange uniform autographs at the top of this post that are in my orange uniform autograph collection, I have his 2008 Bowman Prospects card headed into my collection. Somehow, I have neglected to scan that card, but will try to do so at some point.
Good luck Joe!