Swans defender Neil Taylor has been ruled out for four to six weeks due to a haematoma (severe bruising and swelling) on his thigh.
Taylor picked up the injury in the first leg win over Petrolul Ploiesti in the Europa League Play-off at the Liberty Stadium last week.
It means the left-back will miss the return match in Romania this Thursday and is likely to be sidelined for Sunday’s trip to West Brom along with the games against Liverpool and Crystal Palace in the Barclays Premier League.
Swans head physio Kate Rees explained: “Neil picked up a slight dead leg in the Europa League game last Thursday but he was able to train on Friday and Saturday.
“However, the haematoma re-bled on Sunday and he was admitted to hospital as a precaution.
“While there is no serious muscle or tissue damage, he suffered severe swelling and bruising to his thigh which will take between four to six weeks to clear up.”
Nathan Dyer will also miss Thursday’s Europa League tie due to a current hamstring injury.
Meanwhile, S4C will broadcast live coverage of the second leg in Ploiesti.
The game kicks off at 8.30pm local time (6.30pm GMT), with coverage starting on S4C from 6.10pm (GMT).