Former Arsenal manager Arsene Wenger has backed Ole Gunnar Solskjaer's decision to bench his former player Alexis Sanchez, with the Frenchman suggesting Anthony Martial has made the left-wing position his own at the club.
Martial has blossomed this season, scoring nine goals in 20 Premier League appearances so far, while he has managed to hit the net three times in all competitions since Solskjaer's appointment as interim boss.
Chile international Sanchez, meanwhile, has struggled to force his way into Solskjaer's plans, with an injury at the start of the Norwegian's tenure not helping matters, coupled with the improvement in form of his team-mates.
Indeed, Sanchez has not shown his best since swapping Arsenal for United in January 2018 and has scored just five times in all competitions for the club since then.
And the 30-year-old again found himself on the end of criticism for his latest display after replacing Martial at half-time in United's 2-0 home defeat against Paris Saint-Germain, with the game scoreless at the break.
Despite signing Alexis for Arsenal back in 2014 from Barcelona, Wenger believes Solskjaer's decision to leave him out is completely justified.
"[Sanchez] has lost his position, but he plays in the position of Martial," Wenger told beIN SPORTS.
"Today, who would dispute that Martial is indispensable for Man United? That's competition. That's fair competition in my opinion."
With both Martial and Jesse Lingard having suffered injuries on Tuesday night, Sanchez is likely to get a chance to prove himself in the coming games, starting with the trip to Stamford Bridge in the FA Cup to face Chelsea.
It remains to be seen if he will start, though, with the likes of Marcus Rashford, Romelu Lukaku and Juan Mata all also potential options across the attacking line.
Solskjaer, meanwhile, has admitted he is unsure what to do to help solve Alexis's struggles at United, suggesting it's down to the player to rediscover his best form.
He told reporters after the PSG game:" I can't do anything about Alexis. He needs to find himself as we know there is a quality player there."
After United face Chelsea on Monday they turn their attentions back to the Premier League and a potentially daunting fixture with title-chasing Liverpool.
The return leg against PSG in the Champions League, meanwhile, is scheduled for March 6.