Alexis Sanchez is still a top-class player - Robson

The ex-Red Devils captain has backed the Chilean to rediscover his form, with it vital that he helps Romelu Lukaku to carry the goal-scoring burden

Alexis Sanchez remains a “top-class player” in the eyes of Manchester United legend Bryan Robson, with the Chilean being backed to rediscover his best form.

Having been acquired by the Red Devils in January, the 29-year-old forward has struggled to produce his best.

He has managed just three goals in 21 appearances, with his account yet to be opened in the 2018-19 campaign.

Robson is, however, convinced that a summer without World Cup duty will benefit the former Arsenal and Barcelona star, with United needing to be patient as a proven performer gets fully up to speed - with Chile having agreed to offer him rest him again during the current international break.

The former Old Trafford captain said after Manchester was named the Greatest Sporting City 2018: “Sanchez is a top-class player. But we haven't seen the best of him at Manchester United so far.

“But I'm sure he'll get to the top of his game. This summer was the first summer he's had off for several years, and that should do him good.

“Sometimes, though, when you have a free summer and a fair few weeks off, it can take a little bit more time to come back really sharp and to get into the season.

“These first few games of the season are maybe just what he needs to sharpen him up and then hopefully we'll see the best of him for the rest of the season.”

Robson admits it is vital that Sanchez does find his spark, with Jose Mourinho requiring his other attacking talents to help Romelu Lukaku carry the goal-scoring burden if a Premier League title challenge is to be pieced together.

The ex-England international added: “I think the main thing for Lukaku is to keep getting into those goal-scoring positions.

“You go through periods where you will score a lot of goals and a striker will go through a barren patch where he doesn't score for a few games.

“But with Rom, he just needs to keep getting into those positions that he managed at the weekend and he will get goals.

“The one thing that's guaranteed, as long as he stays free of injury – he will get up to the 30-goal mark for United again this season.

“It's also a matter of Sanchez, [Jesse] Lingard, [Anthony] Martial and [Marcus] Rashford all getting into double figures this season in terms of goals, if we're really going to challenge for the title.

“Lingard did well in terms of goals last season, getting into double figures, and it can't all fall on Lukaku.

“There are going to be periods in the season when he goes through that barren spell and doesn't score.

“When that happens, there have to be other people there who can score goals for United if we're going to be challenging for trophies.”