Atletico Madrid defender Juanfran set to miss both semi-finals with hamstring injury.
"Juanfran took tests which determined that our fullback suffered an injury to the hamstring in his left leg. I think he has little chance of playing on Thursday in the first leg, but he will be back for the second," said Simeone.
Spaniard was substituted in home draw with Real Betis in La Liga on Sunday and was replaced by Sime Vrsaljko.