Diego Costa is an injury concern for Chelsea's crucial Premier League match against Liverpool at the weekend after he lasted just 30 minutes in the League Cup exit at Stoke City.

The Spanish striker had to be sent to hospital after colliding with Stoke midfielder Charlie Adam and suffering pain to his back and rib.

It's not yet clear how long Costa, who clutched his side while waving for medical staff, will be out for.

Chelsea are likely to offer an update at some point today.

When asked about the injury, Chelsea manager Jose Mourinho was unsure of its severity.

"He is in the hospital - I don't know," said the Portuguese, who also blasted Chelsea's critics for suggesting he had lost the dressing room.

Chelsea injury news and suspensions Show all 4 1 /4 Chelsea injury news and suspensions Chelsea injury news and suspensions Thibaut Courtois (goalkeeper) The Belgian goalkeeper injured his knee during training. He has so far missed all but three matches for Chelsea this season and will likely be out until early December. GETTY IMAGES Chelsea injury news and suspensions Branislav Ivanovic (defender) Injured his hamstring while on international duty, expected to be back at the end of October. Chelsea injury news and suspensions Pedro (forward) The Spaniard has what has been reported to be a a minor knock but he has now missed Chelsea's last three matches, last playing in the 17 October win against Aston Villa. Expected to return against Liverpool Chelsea injury news and suspensions Diego Costa (striker) Hurt his back/rib in the League Cup defeat to Stoke and had to go to hospital. His status is currently unknown but he may be a doubt for Liverpool clash Reuters

Mourinho said he didn't know if Costa would return for the Liverpool match.

Chelsea 2-1 Stoke: Jose Mourinho made to sweat over Costa injury