The Portuguese manager is desperate to bolster his forward line during the summer transfer window and was heavily linked with a move for Antoine Griezmann. The Frenchman is now unavailable after Atletico Madrid's transfer ban was upheld by the Court of Arbitration for Sport (CAS) on Thursday (1 June) and Robson believes the Arsenal forward is the perfect alternative.
The Chilean attacker, who will enter the final year of his contract with the Gunners next month, is yet to commit his future to the club and could be available for transfer. Sanchez recently revealed that his future will be sorted out in the summer and his uncertain situation has attracted interest from a number of clubs in England and abroad.
Premier League champions Chelsea and Manchester City have been heavily linked with moves for the prolific forward, while Bayern Munich have also made enquiries over the availability of the attacker. Arsenal are desperate to keep him and have reportedly offered him a new deal worth £275,000-a-week ($354,062) but could cash in on Sanchez should he fail to agree a new deal.
Sanchez has been impressive since his move from Barcelona in 2014. The 28-year-old scored 30 goals and provided 19 assists in 51 appearances in all competitions for Arsenal in the recently concluded campaign and Robson believes he will be a perfect fit for United as he is proven at the highest level in the Premier League.
"His character is right, he is a tough player, really skilful, and he works really hard. He can score goals and create goals," Robson said, as quoted by the Mirror.
"When you put all that package into one, he's exactly the type that we would like here.
"Remember he has played at a club like Arsenal, where you've got to be able to handle pressure. I think he's 100 per cent guaranteed," the former United midfielder added.