He's been putting his pace, skill and strength to good use lately, a lot better then he was before. Before whenever he played on the wing he'd be pretty ineffective, have a few nice touches but ultimately do nothing with it. The last few times we've seen him however he's been getting past players, using his physique to get past them and actually looked to make chances, and had some good decision making. He just needs to keep doing that and be more productive because he certainly has the talent and physique to be a top player, its just the mindset that I wasn't sure of before. He has to try to be more decisive, make a difference, get himself into goal scoring positions and actually make them count which he wasn't doing for the first few months of the season.
Shouldn't start up front right now, Mata is simply a world class player so he needs to start behind Rooney of course, but Welbeck has a chance to make one of the wing positions his own and offer some pace. If we play Kagawa/Januzaj on the other side, we have a fluid system anyways with everyone moving around and comfortable in playing anywhere, and Welbeck or Nani would fit into that no problem.