The 41-year-old former German international has rejoined his old club to aid Arsenal's injury crisis which has seen keepers Lukasz Fabianski, Wojciech Szczesny and Vito Mannone all sidelined.

The rolling monthly deal, until the end of the season, will mean Lehmann can offer experienced back-up to Manuel Almunia, with whom he had a testing relationship before leaving in 2008.

Gunners boss Arsene Wenger, however, has no qualms about putting the pair together again - and Lehmann cannot wait to get started.

"I have kept myself fit since the end of last season and I am ready to contribute at any time for the team," said Lehmann, who played every match of as Wenger's `Invincibles` won the 2003/2004 title.

"I have many great memories from my previous time at the club and Arsenal has always had a place in my heart."

Lehmann added: "It is special to be coming back. I can't wait to start working with the team again and I look forward to contributing as much as I can, both on and off the pitch during this time."

Almunia and Lehmann had previously battled bitterly for the number one spot.

At the height of the acrimony between the two, Almunia went as far as claiming: "To have someone here who hates me is just amazing. I know he hates me."

Wenger, though, insists the duo can work in harmony as Arsenal aim to bounce back from recent disappointments to stay on course for the Barclays Premier League crown.

"There has been much more said about that [relationship] than what happened. There is a lot of respect between the two goalkeepers," Wenger said.

"I think Jens Lehmann will get the best out of Almunia, because he will show him every day he is ready to fight for his place - as he has always been. Almunia will be motivated by that."

Arsenal will be without injured trio Alex Song, captain Cesc Fabregas and England winger Theo Walcott at The Hawthorns.

Centre-back Thomas Vermaelen, meanwhile, is not expected to feature again this season as he recovers from an Achilles problem, while Johan Djourou will be out for at least six weeks with a dislocated shoulder.

Wenger feels despite missing out on the chance of three trophies in the space of a fortnight, there is still all left to play for as Arsenal look to overturn United's three-point lead, while also having a game in hand.

"The atmosphere has not been at the highest level I have known here," said the Arsenal boss, "but we have so much to go for which must be much bigger than our disappointment."