Former Chelsea defender Jason Cundy wants to see the club move for RB Leipzig stopper Dayot Upamecano.
Upamecano has established himself as one of the continent's top defensive talents during RB Leipzig's run to the Champions League semi-finals.
Cundy told talkSPORT: "Largely, you look at the two squads, they went into [the quarter-final] as second-favourites, especially losing Timo Werner as well.
"You've got some big names, some household names in football in the Atleti team but I have to say, the boy at the back, Upamecano, what a performance.
"I was looking at him thinking, as the game was developing, 'this was the first time I've had a close look at your game' and I was watching him and he was just immense.
"I was thinking: 'Chelsea could do with him'.
"He's 21 years of age, it's the best performance I've seen of a young centre-half in a very, very long time."
