The Atletico Madrid forward is urged to follow idol David Beckham and move to Old Trafford.
Barcelona hold a slender advantage heading into the second leg of the Copa del Rey semi-final.
Catalans host Athletic Bilbao on Saturday following 1-1 draw at Real Betis.
Catalans host Basque side before Tuesday's Copa del Rey semi-final with Atletico Madrid.
Atletico Madrid's Antoine Griezmann is Mourinho's priority summer transfer target.
United to reportedly offer Griezmann a contract worth £15m a year.
Jose Mourinho has reportedly made Griezmann his priority transfer target.
Barcelona face a tough test against Atletico Madrid in the first leg of the Copa del Rey semi-final.
Sanchez has 18 months left on his contract at Arsenal.
Griezmann has been heavily linked with a move to United after the end of the season.
Griezmann is also reported to be a priority for Manchester United manager Jose Mourinho.
Silva, 22, has scored four goals in 19 league appearances for Monaco this season.
Reports suggest the France international is United's new priority target.
Costa is also attracting interest from Chinese club Tianjin Quanjian.
Cope says that Belgium international has already told his teammates he wants to return to La Liga.
Griezmann is competing with Lionel Messi and Cristiano Ronaldo for Best Fifa Men's Player Award.
Griezmann has been in brilliant form for both club and country over the past year.
Recent reports claim that Jose Mourinho is likely to meet his £84.6m release clause in the summer.
Spaniard recently admitted he tried to return to Atletico Madrid during the summer.
Both Real and local rivals Atletico were subject to a two-window ban from Fifa back in January.
Portugal captain won both the Champions League and Euro 2016 during a memorable year.
The Uruguayan is among the most excitng young defenders in world football.