RAFAEL BENITEZ was last night reeling from a double injury blow as Xabi Alonso and Daniel Agger were struck by the curse of the metatarsal.

Scans yesterday confirmed both Liverpool players have suffered a broken bone in their foot and now face between four to six weeks on the sidelines.

It’s a major setback for Anfield manager Benitez, with Agger and Alonso almost certain to miss a run of games that includes Premier League fixtures against Everton, Tottenham Hotspur and Arsenal and Champions League ties against Marseille and Besiktas.

Danish international Agger complained of discomfort in his right foot during the week and was consigned to the bench against Porto in the Champions League on Tuesday.

Alonso, who was wearing a brace on his injured left foot on the flight back from Portugal yesterday, initially suffered his damage during the goalless draw at Portsmouth last Saturday.

The midfielder was then ruled out of the 1-1 draw after aggravating the injury during the training session in the Estadio do Dragao on Monday.

Losing Agger in particular is a huge concern to Benitez, with Sami Hyypia and Jamie Carragher the only other senior centre-backs on the Anfield books after the failed attempt to sign Gabriel Heinze from Manchester United during the transfer window.

Benitez has previously suggested Alvaro Arbeloa could prove a temporary option at the heart of the defence, and that there may be opportunities for reserve team players such as Jack Hobbs.

One piece of good injury news for Liverpool is that John Arne Riise will be available for the weekend visit of Birmingham City.

The Norwegian has missed the last two matches against Portsmouth and Porto with a groin problem.

“I picked up the injury playing for my national team but a scan showed it wasn’t a serious problem,” said Riise. “I missed four or five days training but I’m a quick healer and thankfully I’m fit again now.”

Meanwhile, Jermaine Pennant is hopeful his red card on Tuesday does not affect his chances of breaking into the England squad.

The winger is desperate to impress Steve McClaren, and said: “I’m sure the manager won’t hold the sending-off against me. I hope it won’t go against my name.

“It’s the first time in my senior career I’ve been sent off. I was once sent off in a friendly under-18 international, but that’s the only other time, so my disciplinary record isn’t bad.

“I don’t think it is going to raise questions about my performance or my ability as a player. It is just one of those things. There are many great players who have been sent off, players who have played for England , I hope it is’'t held against me. We will have to wait and see.”