Bayern Munich boss Pep Guardiola should take charge of "an average fifth-division side" rather than a job in the Premier League if he is to prove his worth, according to the man in charge of the German FA (DFB)'s coach training facilities.
Frank Wormuth, who also serves as Germany's under-20 coach, said Guardiola was "an outstanding coach" but suggested that his success with Barcelona and Bayern had not been sufficient to warrant his reputation as the world's best.
Guardiola began his coaching career with Barcelona B in 2007-08, where he achieved promotion from Spain's fourth tier, before embarking on a hugely successful four-year spell with the senior side in which he won 14 trophies, including two Champions League successes and three La Liga titles.
With Bayern, he has so far won trophies including two Bundesliga titles and one DFB Pokal as he approaches the final months of his three-year deal, when he will move on in search of a new challenge in the Premier League.
Manchester City, Manchester United, Chelsea and Arsenal have all been credited with an interest in the Catalan, while even Real Madrid were reported to have sounded the former Barca boss out to gauge his interest.
When Suddeutsche Zeitung noted that Guardiola will effectively have his pick of top clubs this summer, Wormuth replied: "Pep Guardiola is an outstanding coach but, with all due respect, he has so far only coached outstanding teams. I would love to see him at an average fifth-division side."
Wormuth has been in charge of the DFB's coaches training facilities since 2007, and all future Bundesliga coaches from Germany have to go through his coaching course. The DFB football coaching licence carries the same significance as the UEFA Pro Licence.
"There are tactical wizards in the third league," he added. "Should we call someone, who is highlighted by the media, 'the world's best coach'? There are many good coaches who put in great performances with players of lesser quality."
Guardiola has received widespread praise in Germany for the constant evolution of his tactics and starting formations as well as his game management, but he has also faced criticism in some quarters, with Germany legend Lothar Matthaus saying in December that he "can't coach a defence."
Wormuth said: "During my courses, I show my pupils that a team plays three or four different systems during a match without realising it.
"But, of course, at FC Bayern Munich, David Alaba can play three positions on a similar level -- you can do everything there. At other clubs, defenders just play long balls, and when the defender has to play on the right wing it just doesn't work out."
He added: "Generally speaking, whether a coach is successful or not comes down to the small situations, what he says when things don't go that well.
"And I am not talking about the major crises, but rather those little things during a match -- to feel when a player has a negative vibe and withdraw him, to spot that the opponent has a problem on the left side and utilise that.
"Those are the details of the everyday business, which are highly interesting and identify a good coach."