The Netherlands international moved to the 20-time English champions from Eredivisie holders PSV Eindhoven in a £25m deal in the summer transfer window.
Memphis disappointed in United’s 2-0 loss to Liverpool in the first leg of their Europa League last-16 clash on Thursday night after he brought down Nathaniel Clyne for Liverpool’s penalty.
The 22-year-old has only scored two Premier League goals in 23 top-flight appearances for Louis van Gaal’s side.
Speaking to BT Sport ahead of United’s clash against West Ham United in the FA Cup quarter-final on Sunday, Wilkins criticised the Dutch starlet.
“A lot of them don’t understand what club they are playing for,” Wilkins said.
“The young man Memphis has come into the side and really hasn’t contributed too much from start to finish. He needs to liven himself up a touch.”
Memphis has scored five times in 11 games in Europe in the Champions League and the Europa League for the Red Devils in his first season at Old Trafford.
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