Buttner's agent Alexander Bursac is furious that his client's wishes to go out on loan have seemingly been scuppered.
Bursac told Voetbal International: "It's unbelievable that Coentrao was not signed on time and, whether that is an error on the part of Real or United doesn't matter.
"We have received assurances of a loan. Alex is not necessarily looking for a guarantee of playing time, but he does not want to spend the entire season on the bench."
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