According to Joel Sherman, the Yankees have optioned Adam Warren, Corban Joseph, and Zoilo Almonte to Triple-A. There was some belief that Almonte had a chance to win the outfield spot, but the switch hitter has hit just .190/.227/.333 in 22 plate appearances. Almonte has never played above Double-A, so he'll have a chance to compete out of Scranton now. The third outfield spot is looking more and more like Melky Mesa's spot to lose.
Corban Joseph was also an option at third base, but his defense this Spring was proven awful. Joseph also put up an unimpressive .200/.286/.200 in his 28 plate appearances, but showed off a much stronger bat in last year's season in Scranton.
Finally, Warren will now enter his third year in Triple-A. He wasn't spectacular in his 3 starts (5.00 ERA but a 1.000 WHIP), but he'd have a chance at a starting job on most other teams. At 25 years old, Warren still has some value, and could be a trade chip with the Yankees' starting depth.
Also, I'm not sure about his status, as on Monday it was reported that Brett Marshall was optioned to Scranton. Yesterday, Marshall appeared in the game against Tampa Bay, and according to the Yankees' website, he's been called up again. I'm not sure if that was a mistake or what's going on, but I assume that Marshall is still with the team.