They probably could, but i really don't see it happening. We are forcing too many scrap results lately. Another replay with Boro will add even more to the congested fixture list. We shouldn't have had that United with World XI this Tuesday, would have been a great time to rest, but now the players have a game after game non-stop. And we are picking up an injury after injury as well. The latest casualties being Van Der Sar, Vidic and Ferdinand. Vidic and Ferdinand should be back in a week but VDS could be longer and if he played today, i'm convinced that we would have won, that's another game we could have done without.
That replay with Boro will also be on Monday only 48 hours after Bolton game. And we HAVE to win against Bolton. Even though they are both at home, those are not easy games, plus the international week and a half coming up, after which we usually get very tired players coming back. Blackburn, will definietly be up for it.
So, if United are to win the treble this season, they will have to really step their game up BIG time and VERY soon, otherwise we will end up only with the premiership and maybe either of the cups. Although having a double would make me pretty happy though. EPL is a priority still.