Adidas chief executive Herbert Hainer has admitted that the global sportswear giant is not impressed with Manchester United's style of play.
The Premier League club sealed a record-breaking 10-year kit sponsorship deal with Adidas worth £750m last summer.
Louis van Gaal's side remain in contention for a Champions League spot in the top flight, but their lack of attacking flair has drawn criticism.
While Hainer is satisfied with the partnership from a business perspective, the Adidas chief is disappointed with recent displays on the pitch.
"Business with Man United is going very well - we sell more shirts than expected," Hainer told newspaper Suddeutsche Zeitung. "We are satisfied, even if the current playing style of Man United is not exactly what we want to see."
United ended a run of eight games without a win when they sealed a 2-1 victory over Swansea City at the weekend.