Jens Lehmann is to sign a short-term contract at his former club Arsenal before this weekend's Premier League visit to West Bromwich Albion to ease the title challengers' immediate injury concerns and provide cover for Manuel Almunia.

The former Germany international, who spent five years with Arsenal up to 2008, is a free agent having retired from the game in 2010 after two seasons with Stuttgart back in the Bundesliga. The 41-year-old can be signed outside the transfer window as he is without a club, with Arsenal to assess his fitness in training sessions over the next few days before confirming his return to the Emirates most likely until the end of the season. "Arsenal have a goalkeeping emergency at the moment," he said. "I'm glad I can help."

Arsène Wenger has been denied Wojciech Szczesny, who dislocated a finger and damaged tendons as Arsenal were eliminated from the Champions League at Barcelona last week, and Lukasz Fabianski (shoulder) in recent weeks. Vito Mannone, on loan at Hull City, is also out by a thigh problem. That had left Almunia as the club's only senior goalkeeper, with the teenager James Shea, a 19-year-old England youth international, recalled from a loan spell at Southampton but considered too inexperienced to be risked as yet in the Premier League.

Wenger admitted last week that he would seek to sign a back-up – "We will look for an emergency goalkeeper and I have someone in mind." – on a short-term basis to provide cover over the run-in, with Lehmann, a player familiar with all things Arsenal and a reminder of past successes, an ideal instant solution.

The German made 199 appearances for Arsenal after signing from Borussia Dortmund for £1.25m in 2003 as David Seaman's replacement, and was Wenger's No1 over the course of the Invincibles' season of 2003-04, and for the FA Cup final victory over Manchester United when the club gained their last trophy in 2005.

Lehmann started the 2006 Champions League final against Barcelona in Paris, when he was sent off in the 18th minute and replaced by Almunia, who was effectively first-choice from early in the 2007-08 campaign.

The goalkeeping pair endured an occasionally fractious relationship, with the Spaniard unhappy with Lehmann's criticisms of his form and ability. Lehmann had described losing his place to the Spaniard as "a humiliation". "To be sitting on the bench behind somebody who only started to play when he was 30 is not funny," he said.

"I know he hates me," Almunia told this newspaper in April 2008. "I'm an easy going person. I like to treat everyone with respect and I see everyone as equals. I treat people the way I would like to be treated myself. To have someone here who hates me is just amazing."

Bridges were built to a certain extent at the end of the German's spell at the club, and he will return with his role merely as an understudy to Almunia – who has lost his position as first choice, first to Fabianski and then to Szczesny – very clearly defined.

Lehmann had been due to spend six weeks at Arsenal's London Colney training complex, albeit on a coaching course to gain his badges, but will now prolong his playing career instead.

He held talks with Wenger on Monday and will now be monitored in training over the next few daysto determine his fitness and capabilities. His last game was for Stuttgart against Hoffenheim on 8 May, 2010, although he is understood to have maintained a good level of health through gym work in the period since.

The former Germany international has been working in the media since retiring from the game and has attended matches at the Emirates already this season, as a pundit for English and German broadcasters.

He was at Camp Nou to witness Arsenal's 3-1 Champions League second-leg defeat last week, when Szczesny sustained his finger injury, and is expected on the bench at the Hawthorns on Saturday.