Rabbi Matondo has a release clause in his contract which would allow him to move to Manchester United for €60 million this summer.
MEN Sport understand Welsh winger Matondo included a clause in his deal to move to FC Schalke last January which would see him allowed to move to any English side if they matched the fee.
However, former club Manchester City would have a potential advantage in any deal for the 19-year-old with their own buyback clause which could see Matondo rejoin them for €46.5 million.
MEN Sport revealed earlier this month United are monitoring Matondo as a possible back-up target for Jadon Sancho this summer, with the Wales international viewed as a more cost-efficient option.
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