The Elland Road side returned to the top of the Championship table, but their skipper was hooked just after the 30 minute mark last night.
He appeared to pull his groin and was swiftly sent down the tunnel.
Scotland could be doing with Leeds man Cooper
Scotland are short on centre-backs just now so they could be doing with Leeds man Cooper. Scott McKenna is still out injured, and if Cooper were to drop out, there aren’t that many options.
It’s a shame for the player too. He had just made his Scotland debut last month , starting the Belgium and Russia matches at Hampden, although they both ended in defeat.
Grant Hanley looks set to be his main competition for a start, with Charlie Mulgrew a clear favourite of Clarke’s. The Wigan defender has played every match during his tenure.
It’s a blow for Cooper. After helping Leeds keep four clean sheets this term and helping them start the Championship season brightly, the centre-back was in decent form heading into this set of games.
Hopefully his injury isn’t serious and he can still be available for selection next week.