Frederic Veseli's agent claims the player left Manchester City for neighbours United because he felt the Blues' priorities have moved from nurturing youngsters.
The 19-year-old was United's only deadline-day signing and will initially link up with Warren Joyce's reserve-team squad before pushing for a chance at senior level.
Skipper of the Swiss Under 17 side crowned world champions in 2009, Veseli hoped to get his chance at City this term after being part of Roberto Mancini's squad for the pre-season tour of the United States.
However, the opportunity never came and as Veseli grew disillusioned, in stepped United, whose manager Sir Alex Ferguson has never been afraid to give youngsters a go.
"These days, Manchester City are chasing titles and major trophies," explained Veseli's agent Adam Bouskouchi said.
"It is difficult for them to have faith in youth because they obviously feel experience is the best way for them to get where they want to go.
"But that attitude didn't help Freddie, who just felt like he wasn't progressing.
"On that pre-season tour, both Roberto Mancini and - director of football - Brian Marwood said how well he had done. But since then, nothing."
Bouskouchi admits Veseli had offers from several clubs, but was persuaded to move to Old Trafford after speaking to Sir Alex Ferguson.
"Freddie spoke with several clubs, here and abroad," added Bouskouchi.
"But he wants to be a top player in England and when Sir Alex spoke to him, it made such an impression.
"He is a difficult man to say no to and his track record was enough for Freddie to feel he was making the right choice to join United."