Tatum began the season at Triple-A Norfolk and batted .195 in 31 games with the Orioles. He had three doubles and seven RBIs.
Tatum beat out Chad Moeller for the backup job in 2010 and batted .281 in 43 games, with four doubles and nine RBIs, but the Orioles made Jake Fox the backup coming out of spring training this year. Tatum made it back to Baltimore during the summer because he was a defensive upgrade over Fox, who came off the 40-man roster and later had his contract purchased.
The 40-man roster includes only two catchers: Fox and starter Matt Wieters. The Orioles will almost certainly sign a catcher over the winter, perhaps to a minor league deal with a spring training invite.
Triple-A Norfolk's roster included catchers Adam Donachie and John Hester. Double-A Bowie catcher Caleb Joseph batted .257 with seven homers, 41 RBIs and a .692 OPS in 107 games. He wouldn't be expected to make the jump to the majors by Opening Day 2012.
MLBTradeRumors.com first confirmed that the Astros claimed Tatum.
Instant update: Make that one catcher on the 40-man roster. The Orioles just announced that Fox and pitcher Chris Jakubauskas cleared waivers and were outrighted to Norfolk. They also confirmed the Tatum transaction.
Fox, 29, batted .246 with two homers and six RBIs in 27 games. Jakubauskas, 32, was 2-2 with a 5.72 ERA in 33 games, including six starts. They can decline the outright assignments and become minor league free agents.
The Orioles have 36 players on the 40-man roster.