By Samuel Meade Gary Neville admits Arsenal have a question mark hanging over them following their defeat to Aston Villa. The Gunners surrendered top spot as they were stunned at the Emirates, with their loss allowing Manchester City to put themselves in pole position. Their attention now turns to Bayern Munich, who they face in Germany on Wednesday night. Mikel Arteta’s side drew 2-2 in the first-leg and need to win at the Allianz Arena to go through to the semi-finals. They’ll be licking their wounds after Sunday’s reverse but will be aiming to avoid the collapse that marred last season. Nev…