He said he'd be happy to switch if that's what the manager wanted and he's used to playing on the wing as his normal position. "Anywhere in the attacking positions is my favourite, but helping the team score is what I try to do wherever I play." is what he said. If you look at the stats, he's played in the three spots (left, right, centre) about equally this season.
Either way, to be blunt: who gives a smurf about where they prefer to play? The manager picks the team and has put a lot more time and research into Uruguay and their weaknesses than they have. It's that sort of trout that's seen us indulge Rooney and try to play Gerrard and Lampard together over the years. Sterling might prefer to play in goal but tough trout because we don't need you there, we need you at no 10. He caused plenty of damage there against Italy and Uruguay's Centre Backs look suspect. Welbeck looks a damn sight better on the flanks than he does the middle too, fwiw.