Yossi Benayoun and Albert Riera added to Liverpool's injury concerns when both were ruled out for up to a month due to hamstring problems.

Both players limped out of Monday’s Premier League draw against Birmingham at Anfield, adding to manager Rafael Benitez’s injury concerns.

Daniel Agger and Glen Johnson also suffered injuries in the same game while the club continue to monitor key duo Steven Gerrard and Fernando Torres.

"We will have to wait and see how they progress but hopefully in three weeks they could be available," manager Rafa Benitez explained.

"We are disappointed because there are too many things at the moment we can't change. Both players are wingers as well and for them to be out at the same time is bad news for us."

There was better news on other injured players, with Benitez hoping the international break would allow his depleted squad time to recover for the next game against Manchester City.

"Sometimes a break comes at a bad time because you don't like to see your players flying all over the world but this time it gives us a chance to get some players back," said the Spaniard.

Benitez said defender Agger, who suffered a knock in the 2-2 draw against Birmingham City on Monday and withdrew from Denmark's friendlies against South Korea and United States, could be back in training in a few days.

The condition of Johnson, who pulled out of England's squad for Saturday's friendly against Brazil, was also encouraging.

"Hopefully it's not too serious and he could be available again in a week," said Benitez.

Torres will need two or three weeks treatment on his groin strain.

"I was talking with him this morning and he is doing well," said Benitez. "Hopefully he can be running in a few days and we will see how he progresses."