David Alaba could well be on his way out at Bayern Munich but Michael Ballack does not believe Dayot Upamecano is ready to replace him.
Versatile defender Alaba will be out of contract at the Allianz Arena at the end of June and has been heavily linked with a move to Real Madrid.
Bayern have been tipped to bring in Upamecano should the Austria international opt to leave, with the RB Leipzig centre-back reportedly available for €42million.
Prior to Saturday's Bundesliga games, Upamecano had been involved in more clean sheets (seven to four) and made more tackles (22 to 14), recoveries (149 to 110), blocks (11 to nine) and clearances (41 to 38) than Alaba in the top flight this season.
While he has contested significantly more duels than Alaba (134 to 79) their success rate is similar, with the Bayern defender having the slight edge at 55.7 compared to 54.5.
Ballack acknowledges Upamecano's physicality would be useful and thinks he could improve at Bayern, but he does not see him as someone capable of immediately filling the void Alaba would leave.
"He is a completely different kind of player to David Alaba, who had a substantial part in building this new era of Bayern. He was a flagship for them, after all he was a product of their youth system and played there from a very young age," Ballack told Stats Perform News.
"He is now at an age where he wants to try out something different. You have to respect that and accept it as well. Of course, you can talk about the reasons, but this is the way it is.
"He is a very versatile player who lately played as a centre-back. He fulfilled this role completely. He can also play in the midfield and is therefore an all-round player who is hard to replace for Bayern due to his character and standing within the team. If Bayern will lose him, then it will be a significant loss for them.
"Upamecano is a player on their wish list. I heavily doubt whether he is ready for the role at Bayern. He is still very young and has outstanding moments, primarily due to his physicality.
"I'm very, very certain that he will improve a lot at Bayern. When you play together with high-class players, then you will improve automatically even in training.
"If it comes to an agreement, then this will be expected from Bayern. In terms of physicality, he brings in enough qualities to be of value."
Upamecano has shown he is good with his feet, starting on average 14.6 open play sequences per 90 minutes in the Bundesliga this season prior to kick-off in Leipzig's match against Schalke; that compares to 11.3 for Alaba.
He also ranks closely to Alaba (54.1) in terms of open play build up involvements with 53.6 per 90 minutes, suggesting he could fit in quite nicely with Bayern's style of play.