I think Mascherano is being eased in becasue he was away playing for Argentina over the summer, so he is getting a bit more rest.
If we have a permanent deal nailed down and we exercise that in the summer, then for my money, one of Alonso or Sissoko will be off. I feel the best midfield pairing is Mascherano and Gerrard, as that really does have everything. The other options we have are very good too, but this one is the best partnership.
I half wonder if Alonso might go back to Spain next summer, since he really is too imperious to not be a main man, and then Sissoko and Leiva will be the understudies to Mascherano and Gerrard. Don't get me wrong, I'd love to keep them all, but I don't think it will be possible beyond this season.