Dundee United manager Gordon Chisholm's misery at losing 2-0 away to Aberdeen was compounded by injuries to David Fernandez and Paul Ritchie.
"David hurt his hamstring and I don't know how bad it is yet," said Chisholm. "We will have to find out on Wednesday.
"The same applies to Paul Ritchie, who suffered a dead leg, but we hope he will be fit for Sunday's game.
"We were on top after the break, but I was disappointed to lose two goals when Aberdeen put us under pressure."