The saying goes that a picture says a thousand words, and that’s never rung more true than the image of a disconsolate Alexis Sanchez during Arsenal’s 5-1 defeat by Bayern Munich on Wednesday night, with the Chilean displaying all the signs of a player that has outgrown a club that simply isn’t cut-out to challenge for the Champions League.

Arsenal are on course for a seventh consecutive last-16 exit in Europe, with a second-leg fightback highly unlikely given the gulf between the Premier League side and a brilliant Bayern in yesterday’s first leg.

The constant failings in Europe are part of the reason why top goalscorer Sanchez is reluctant to commit his future to the club, with his contract up for renewal at the end of next season. The 28-year-old has so far refused to agree a deal with the club due to a combination of his wage demands and a concern that the club’s ambitions do not match his own.

Sanchez has proven Arsenal’s saviour this season, scoring 20 goals across all competitions – the only Arsenal player to reach double figures in the Premier League this season – and their dependency on him shone through once again on Wednesday, with the Chile international scoring Arsenal’s only goal of the match.

With his future uncertain, Arsenal should be concerned with his reaction towards the end of the match on Wednesday. As his teammates trudged back into position following Bayern’s fifth goal – scored by substitute Thomas Muller – Sanchez stood, alone, on the opposite touchline to the dugout, hunched over in despair.

Alexis Sanchez crouches on his own after Thomas Muller scores Bayern Munich's fifth goal against Arsenal (Twitter)