RB - Gino Peruzzi is fantastic. But even better than him at that position are two players you already have - Rafael and Phil Jones. With those 2 at RB, trust me, you won't need anyone else. Plus, Jones provides HG and Rafael HGC, which is a big bonus.
For DLP, actually, James Ward-Prowse is fantastic. Of course Carrick is brilliant as well. And Nick Powell, when he gets back from loan.
For MR/ML - Tom Ince should be available for around 5.5 Million $;; I got him at Soton in the first season, and now all the top clubs are bidding for him, which I'm rejecting. MR, try retraining Wilfried Zaha. He grows to be one of the best RM/AMR ingame. Oxlade Chamberlain is outstanding as well, but he won't be available for United.