What have we done to him actually? He was given a chance on a wing and in midfield, he failed to cement his spot in either of those positions, he failed to adapt his game to LVG's instructions. Look at Herrera, took him time to get into our XI due to subordination issues yet when he's turned it around he played nearly every game and became one of our leading outfield players.
You'd think we gave him a mining pick and asked him to work in quarry.
We never gave him the chance to settle properly. That's been the problem and it's down to van Gaal.
We played him as a LCM for the first few games: He played alongside Fletcher in CM against Burnley and LCM from QPR -Everton.
We moved him to the left wing for the games against WBA to Palace.
He then played right wing in a 3-5-2 against Arsenal, and then got injured playing right wing in a 4-4-2 against Hull.
Following his return from injury, he got injured again against Villa playing on the left.
Following his return from his second injury, he played as a SS against Yeovil, Southampton and QPR (seriously...? wtf?).
He then finished his first season (as a starter) by interchanging between the left and right wing.
He and Rooney have had it the worst, this season. Constantly shifting positions, but have got on with their jobs and still contributed brilliantly towards the cause. Not a coincidence that our two best players are the ones who have contributed the most whilst playing in, nearly, every possible position. It's a testament to how talented the two are and how we should have played them in their rightful positions to be able to extract the best out of them. Injuries haven't helped us, but neither did our manager. Rooney and di Maria should have been two players nailed on to start in their best positions.