Patrick Kluivert's move to Valencia could be in jeopardy after a knee problem was detected during a medical, Spanish sports daily Marca reported on its website on Friday.
The Dutch striker was due to sign a three-year contract with the Primera Liga club after being released by England's Newcastle United last week.
Marca
said an initial medical examination had revealed a knee problem, adding that further tests would be needed to assess whether the move could go ahead.
Kluivert was originally scheduled to be officially unveiled on Friday evening.