The Chile international signed for the Red Devils from Arsenal in the January transfer window but struggled to have much of an impact at Old Trafford during his first few months at the club.
The 29-year-old struggled to produce consistent form for the Red Devils following his move back in January despite having established himself as one of the Premier League’s top attackers at Arsenal.
Manchester United fans will be hoping to see Sanchez hit top form for Jose Mourinho’s side in his first full season at the club.
And Red Devils legend Robson is expecting to see the Chile international hit top gear for Manchester United in the coming weeks and months.
Speaking to Manchester United’s website, Robson said: “He is a top-class player, there is no doubt about that and I think he is a great signing.
“He didn’t play to the top of his form when he first came but I think, maybe, he was trying too hard to impress, not playing his natural game.
“That will all settle down. He knows the manager, he knows how the manager wants to play and I think we will see a really classy Sanchez this season.”
Manchester United will be aiming to challenge for the Premier League title next season after having finished in second place in the table last season and without a trophy.
The Red Devils have signed three players so far this summer after having brought in Diogo Dalot, Fred and Lee Grant ahead of Mourinho’s third campaign in charge at Old Trafford.
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