Dennis Dixon has a separated shoulder

Ben Roethlisberger isn’t the only injured quarterback in Pittsburgh.

On Saturday night, backup Dennis Dixon was dinged up during Saturday night’s preseason game against the Redskins.

Coach Mike Tomlin called Dixon’s condition an “injury to the AC joint,” which is the “glass-half-full” way of describing a separated shoulder.

The degree of the separation isn’t known.  As Ed Bouchette of the Pittsburgh Post-Gazette points out, Roethlisberger suffered the same injury last year, but he missed no games.

The Dixon injury leaves the Steelers will only two healthy quarterbacks, for now — Charlie Batch and Mike Reilly.

Some believe that Dixon could become the No. 2 man on the depth chart this year, possibly prompting the Steelers to sever ties with Batch, who missed all of the 2008 season with a broken collarbone.

Tomlin wouldn’t say after the game whether Roethlisberger will return to practice on Monday.  He suffered an Achilles’ tendon injury on Thursday.