Burnley are set to send the Carling Cup into chaos.
The puzzled Championship outfit want a ruling on whether striker Defoe should have appeared in the second leg - when he was not eligible for the first.
Clarets chiefs have checked rule books and believe they state players must be signed before the 'tie' starts. And as both legs are part of the one result - with aggregate scores and away goals included - they may have a case.
Owen Coyle's heroes were two minutes from Wembley last week after dragging Spurs level 4-4 on aggregate before losing in extra-time - and they were then alerted to a possible breach of the rules.
Defoe was NOT registered as a Spurs player before the first leg, waving to the fans prior to that game, but he had not put pen to paper on the transfer from Portsmouth.
And he played in the second leg at Turf Moor and also chipped in with a late goal - leaving Burnley insiders to study the rule books.