Liverpool are expected to discover the extent of the injury suffered by Milan Baros on Thursday.
Baros, 23, aggravated a hamstring injury representing the Czech Republic on Wednesday and lasted just 18 minutes in the win over Macedonia.
Czech team doctor Petr Krejei said: “The people that have looked at him think the muscle has been pulled.”
“But there will need to be another examination of it before it can be properly assessed.
“But we think it is similar to before and recommend a few weeks’ rest.”
Liverpool are already short of strikers following the sale of Michael Owen to Real Madrid and the broken leg suffered by Djibril Cisse.
Baros added: “I knew what was wrong as it happened before. I knew I had to go off straight away.
“I could feel it as it is the second time I’ve felt the muscle.”