as awesome as he has been this spring, i don't think the team will be able to bring him north, barring a trade of course. wells and rios are set at cf/rf, and koskie is set at 3b. so for 1b/lf/dh they have reed/cat/shea/hinske to get at bats for.
gross has some options left, so i think they'll send him back to the minors, and then call him up during the year if he is tearing it up down there as well, and trade away one of the guys i mentioned above. i don't think it would be wise to have him sit on the bench for most of the year, when he could be playing everyday.