By Editor Wayne Veysey

During what has been a season-and-a-half of mostly majestic performances in an Arsenal shirt, one truism has been that when Alexis Sanchez is fit, he starts.

Indeed, even when the ultra-committed Chilean has not been fit, he has still started.

The quandary for Arsene Wenger is that Sanchez has such match-turning and match-winning potential, and is so desperate to produce it, that the manager has been seduced into selecting the forward when his instinct might have been to be cautious and give him a rest, or at least start him on the bench.

Wenger finally paid the price for trusting in Sanchez’s desire to play in late November when, after weeks of warnings, the player’s hamstring finally pinged and he was forced to spend his first extended spell on the sidelines since joining the club in the summer of 2014.

Following a recovery that proved far more complicated than initially expected – hardly uncommon at Arsenal – Sanchez has looked a shadow of the player who was once in total mastery of the league.

In five matches since returning to the team, he has scored just once, in the FA Cup against Burnley, but it is his performances that are of more of a concern to Wenger and his coaching staff.

Against Leicester on Sunday, Sanchez’s touch was poor, he frequently lost possession and his shooting was either too slow or mis-cued. He was willing – he always is – but one of the team’s three genuinely world-class operators (Mesut Ozil and Petr Cech are the other two) looked the problem rather than the answer to Arsenal’s failure to capitalise on their possession.

Alexis Sanchez is back in full training ahead of Arsenal's clash against Chelsea

Sanchez has struggled since returning from a two-month lay-off

It would not be unfair to say it was one of the Chilean’s worst displays in an Arsenal jersey.

Sanchez’s touch will doubtless return but the two-month lay-off has robbed him of some of his raw speed, that acceleration in small spaces that allows him to evade opponents and set up scoring opportunities.

For the first time in his Arsenal career, it is questionable whether the 27-year-old should be the nailed-on starter that has previously been his right.

With Danny Welbeck making a fairytale return on Sunday, and Theo Walcott, Alex Oxlade-Chamberlain and Joel Campbell seemingly scrapping for one position, there is finally competition for attacking places in Wenger’s team.

Just about in time. Following next Saturday’s FA Cup home clash against Hull, Arsenal host Sanchez’s former club three days later for the first leg of their against-the-odds bid to topple Barcelona at the Champions League last-16 stage. Then, they travel to Manchester United five days later.

For fixtures that will define their season, Arsenal need Sanchez back to his best. If not, Wenger might have to think the unthinkable and consider demoting him to the bench.