Sunderland boss Howard Wilkinson admitted after the game that Reyna had a suspected ligament problem, although at that stage it was not clear whether it was his cruciate or medial ligament which was damaged.
However, scans indicated he had suffered cruciate ligament damage meaning the midfielder will not play again this season and could be out of action for up to eight months.
The injury Reyna has sustained is the same as that sufefred by Gavin McCann in February 2000 and that kept him out until November of that year.
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