Former Bayern Munich stalwart Oliver Kahn believes Germany international Manuel Neuer has taken goalkeeping to "a new level" with his style of play.
The signing of Neuer was greeted with disapproval from some Bayern fans upon his arrival at the club from traditional rivals Schalke in 2011.
He has answered any doubters in emphatic fashion during the subsequent four years, winning the Bundesliga three times, as well as the DFB-Pokal, the Champions League and the World Cup with his country.
Neuer is now widely regarded as one of the world's best shot-stoppers, with Kahn not the first observer to remark on the 29-year-old's distinctive willingness to leave the box.
"Manuel is a sweeper-keeper who has taken the game to a new level, always takes plenty of risks and has made himself an 11th outfield player," Kahn told the official FIFA website.
"He's always available for a pass and is equally strong on both his left and right foot. His team-mates can bring him into the game whenever the situation requires it, and that's a huge plus for any back line.
"In many cases he also tries to defuse situations as early as possible, sometimes from well outside the penalty area. He hasn't yet made a mistake in a vital game; that's just his playing style. Manuel has perfected this skill."
Neuer was at fault for Schalke's goal at the weekend as Bayern recorded a 3-1 victory, but Kahn feels the man who finished third in the 2014 Ballon d'Or race has no flaws in his game.
"I don't think he has any serious issues any more. You're always working to improve your game at this level. As goalkeeping is an art in its own right, you're always trying to perfect each individual facet of the role," Kahn added.
"He's very brave when it comes to dealing with crosses and tries to help the team by coming out of the six-yard box. Nevertheless, mistakes will always happen every now and again, and that's normal. He has strong reflexes and is tough to beat from distance.
"The name of the game now is to maintain this level and work on getting a little bit more out of each area. That's the challenge faced by anyone at Neuer's level."
Having kept a clean sheet in a 4-0 Champions League win at home to Olympiacos on Tuesday, Neuer's next opportunity to impress will come in the Bundesliga this weekend, when Hertha Berlin visit the Allianz Arena.