The Chile international was heavily linked with a transfer to Old Trafford following Louis van Gaal’s appointment but a move failed to materialise.
Vidal rushed back from a knee injury to make himself available for the World Cup in Brazil.
And Marotta says that the 27-year-old is now suffering the effects of failing to undergo a proper rehabilitation schedule following his injury.
“His injury influenced his departure and even now he doesn’t have the best physical condition,” said Marotta.
“For our part, however, there is a clear desire to keep him because we extended his contract.”
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