The Red Devils confirmed a £52m agreement to sign Fred from Ukrainian Premier League champions Shakhtar Donetsk earlier this month.
Manchester United have been regularly linked with a move to sign the Brazilian midfielder over the past few months.
Fred will strengthen Manchester United’s options in the middle of the park following Michael Carrick’s retirement.
The Premier League and FA Cup runners up snapped up Portuguese teenager Diogo Dalot in a £17m deal from FC Porto in their second deal in the summer transfer window.
Dalot is something of an unknown quantity following just eight appearances in the FC Porto senior team.
However, former Manchester United striker Yorke welcomed the addition of Dalot and Fred to the Manchester United team.
“We don’t know too much about Dalot and Fred and they haven’t been tested yet in our league,” said Yorke, speaking exclusively to 888sport.
“Jose has looked to improve as United always does and to do his business as early as possible.
“Every team each year looks to improve themselves by ten per cent but City have set the benchmark and now it’s down to United to respond to that. That’s what we’ll see this summer and the same goes for Liverpool, Chelsea, Arsenal and Tottenham as they look to close the gap.
“A lot of work needs to be done. But I don’t believe that City are 19 points better than United. United had some great results and beat City away and against Liverpool and Tottenham and Chelsea.
“They beat all of the big teams: it was just inconsistency that frustrated everyone. Whether that gap can be bridged remains to be seen but I don’t personally believe they are 19 points better than us.”
Manchester United finished in second place in the Premier League table but ended up 19 points adrift of champions Manchester City.
The Red Devils lost 1-0 to Chelsea FC in the FA Cup final at Wembley following Eden Hazard’s winner from the penalty spot.
Manchester United are looking to win their first Premier League title since 2013 when Sir Alex Ferguson was still in charge.
Read the full 888sport interview with Dwight Yorke, including how he feels the French presence at United can draw in Griezmann.
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