Dejan Lovren will miss Croatia's World Cup qualifier with Finland.
The Liverpool defender featured against Newcastle on Sunday after revealing he had been taking five painkillers to get through matches.
Lovren has been struggling with back and Achilles problems and hasn't been able to train, reports the Liverpool Echo.
He will be assessed again later in the week to determine whether he plays any part against Ukraine on Monday.
“Lovren is playing without training with the help of injections and pills,” Croatia boss Ante Cacic said.
“After every game it takes time for recovery.”
Jurgen Klopp will be hoping that Croatia don’t take any chances with Lovren ahead of the crunch Premier League clash with Manchester United at Anfield a week on Saturday.
Lovren sat out matches against Manchester City and Burnley but took tablets to enable him to play against Leicester City, Spartak Moscow and Newcastle.
“I have problems with my whole body for the last two weeks, my back and now I have hurt my Achilles tendon,” Lovren said.
“I am taking pills so I can play five before every game. I wanted to play, the coach put me in the team, but it is not good.”