The Chilean arrived at Old Trafford from Arsenal in a swap deal for Henrikh Mkhitaryan in January 2018, but has struggled to replicate the form he showed during three-and-a-half years at the Emirates.
Sanchez failed to impress again after coming off the bench just before half-time during United’s 2-0 last-16 first-leg defeat in Manchester on Tuesday.
Ince, who spent six years as a player with the Red Devils between 1989 and 1995, believes the former Barcelona star is doing little to justify his significant salary package.
“The way Alexis Sanchez is playing at the moment is nothing short of a disgrace,” he told Paddy Power.
“The fans deserve better, Ole deserves better, and so do the rest of his team.
“Maybe he has the hump because he’s not in the starting XI, but that’s hardly a surprise.
“He’s been hopeless, completely all over the place. There has to be a decision made about his future at Old Trafford, because it’s not working. But this is the dilemma when you keep sacking managers; players the previous boss bought in on high wages are impossible to get rid of – so you have to try to make them work in your team.
“He’s a million miles away from being at his best, he looks like a completely different player.”
Sanchez has made 19 appearances for United in all competitions this season, scoring just two goals.