Working his way back from a Grade 1 hamstring injury suffered on April 4 in Toronto, Mark Teixeira will begin his road back to the Yankees by playing three innings in a game today. It hasn't been confirmed exactly what that game will be, whether it's a simulated game or a game with the High-A Tampa Yankees, but with the T-Yanks playing in Daytona, the best guess is that Tex will stay behind in Tampa for a sim game.
Teixeira is eligible to come off the disabled list on Sunday and may very well do so, as expected. With a currently full 25-man roster, though, it's unclear as to who will get sent down to Triple-A in place of Teixeira once he returns. I suppose they could send down Scott Sizemore, but he may have to clear waivers first to get sent back to Scranton/Wilkes-Barre and some team would probably claim him in that event. They could, theoretically, send Dean Anna to Triple-A, but he's currently the team's true backup shortstop. They also could send someone down like Cesar Cabral, but that'll shorten the bullpen from a traditional seven-man crew to six.
The Yankees necessarily don't have to send someone down to open a spot up for Teixeira, however; they could send someone to the Disabled List instead. A prime candidate for this would be Brian Roberts. Roberts, who has a laundry list of ailments in recent years, is already sidelined thanks to a bad back. The Yankees have said that Roberts is day-to-day, but there's always a chance Roberts' back troubles could further linger, a la Kevin Youkilis in 2013. They also wouldn't have to wait the full 15 days if Roberts is DL'd, since he's missed the last four days already and it's not like he was hitting (37 wRC+) when he was healthy anyway.
First thing's first, though: Teixeira has to complete his rehab, which he'll start today. It's unclear as to what roster move they'll make if Teixeira is ready by Sunday, but that's a bridge they'll cross when they get there.