Jupp Heynckes feels Manchester City attacker Leroy Sane is yet to become a "top player" and believes the reported Bayern Munich target is not worth €100 million (A$172m).
Sane, 24, was heavily linked with a move to Bayern before suffering a serious knee injury in August last year.
The German giants are reportedly still interested in Sane, but Heynckes – who won a UEFA Champions League and four Bundesliga titles as Bayern head coach – said the attacker was not yet among the world's best.
"He was in good shape before he injured himself so badly. For me, he has not yet made a breakthrough as an absolute top player," he told Welt am Sonntag.
"I think this is a player who is currently at a crossroads. Will he continue to work hard on himself, or will he continue to be just an extraordinary talent?"
Bayern were reportedly prepared to pay at least €100m (A$172m) for Sane, although that may have changed due to the coronavirus pandemic.
But Heynckes does not feel Sane, a 21-time Germany international, is worth that hefty sum.
"He has to be ready to take the next big step because there is no use in flashing the talent every now and then," he said.
"I can honestly tell you that I don't think the price is justified."