"He [Lehmann] belongs in the Muppet Show, on the couch or in a mental institution." Tim Wiese, September 2010.
According to Arsene Wenger, though, 41-year-old Jens Lehmann now also belongs in the Arsenal dressing room. We must wait and see whether the imminent return of the man affectionately known as 'Mad Jens' is a risk worth taking by the Arsenal manager.
Amazement, excitement and plain bewilderment have greeted Monday's news that Lehmann is to come out of retirement, but one of the more bizarre reactions is criticism that it is a move that smacks of desperation on Wenger's part. Well of course it is. Desperation is the state you find yourselves in when three of your four senior goalkeepers are injured outside of the transfer window. Circumstances have conspired to force the Arsenal manager into a particularly difficult corner.
Idiosyncratic goalkeeper signings are not a new phenomenon - Manchester United surprised English football when signing the 36-year-old Andy Goram from Motherwell in 2001, while Manchester City recruited Marton Fulop from Sunderland only last season - and if Manuel Almunia remains fit then Lehmann will not be a factor on the pitch. His fitness, surely impacted by ten fallow months, should not be an issue; however, his presence in the dressing room may well be.
Signed to provide support for Almunia, who has been brought back from first-team exile and thrust back into action following injuries to Wojciech Szczesny and Lukasz Fabianski, the German again finds himself in direct competition with a rival he belittled with enthusiastic regularity during his previous time at the club.
After losing his place to Almunia following mistakes against Fulham and Blackburn at the start of the 2007-08 season, Lehmann famously said of his colleague: "To be sitting on the bench behind somebody who only started to play when he was 30 is not funny". It is little wonder that Almunia admitted to The Guardian in that same season that "I know he hates me".
Though Lehmann has made conciliatory noises since leaving the club, it is hard to escape the conclusion that somewhere in the North London area, Almunia is currently breaking into a cold sweat at the thought of two more months of training sessions with the deadly rival he thought he had vanquished three years ago.
The arrival of Lehmann could inspire the Spaniard. However, it could also undermine him.
Herein lies the difference between the signing of Lehmann and that of Sol Campbell last season, or Wenger's decision to explore the possibility of re-signing Patrick Vieira. Campbell was a widely respected figure and a worthy addition to the dressing room for the short time he spent back at the club; Lehmann, meanwhile, surely has the potential to be a destabilising influence on the goalkeeper he is expected to deputise for.
Clearly, this is not a man afraid to shy away from confrontation. As well as Almunia, Lehmann was famously involved in a public war with Olvier Kahn at international level, and it was one he won as he took Germany's No. 1 jersey for the World Cup finals on home turf in 2006.
Though he is rightly fondly remembered by the majority of Arsenal fans - with his final appearance against Everton on the final day of the 2007-08 season provoking an emotional and very genuine standing ovation for one of the Invincibles - his reputation for trouble also precedes him.
Always willing to indulge in a sneaky push on an opponent, most famously Robbie Keane when he conceded a penalty in the game that secured Arsenal the 2003-04 title, Lehmann was a combustible character. He was also a comic figure, with his infamous diving competition with Didier Drogba in December 2006 going into Premier League folklore and his strange warm-up routines entertaining fans.
This rather eccentric approach to the game was in evidence even more frequently during his subsequent career with Stuttgart: highlights including urinating during a Champions League fixture; sneakily stealing an opponent's boot and placing it on the roof of his own net; and, quite brilliantly, nabbing the glasses right off the face of a critical supporter following a match.
His capacity for high farce should not disguise the fact that he was a central figure in both the unbeaten season of 2003-04 and the Champions League run of 2005-06 - his save from Raul in the last-16 defeat of Real Madrid and penalty stop from Juan Roman Riquelme in the dying seconds of the semi-final against Villarreal are both iconic saves in the club's history.
However, even during times of great personal achievement, that destructive urge reared its head. As Arsenal won the title at White Hart Lane in 2003-04, Lehmann turned a victory into a draw when pushing Keane. In Paris, a rush of blood to the head saw him sent off in the Champions League final.
To say Lehmann is a complex figure would be to understate the matter. His likely return to Arsenal, and the impact it will have, is also a complex scenario to unpick.
As a bridge to past glories, he brings experience of winning trophies - an element painfully lacking in a squad that boasts one Premier League winner in Gael Clichy - and perhaps time has mellowed the man. However, the suspicion remains that the signing of 'Mad Jens' may be a moment of temporary insanity from his manager.