Josko Gvardiol remains "totally happy" at RB Leipzig with "no hurry" to rush into a pre-transfer agreement amid growing links to Real Madrid and Chelsea.

That was the message from the centre-back's agent Marjan Sisic as Gvardiol continues to impress at the World Cup with Croatia, who beat Japan on penalties to reach the quarter-finals on Monday.

Chelsea reportedly had a £77million (€90m) offer rejected before the start of the season before the 20-year-old signed a new contract with Leipzig.

Madrid are said to have joined the growing list of Europe's elite clubs interested in the defender, though Sisic insists his client will not be forced into making a quick decision on his future.

"Regarding a possible transfer in summer 2023, we are in no hurry and I can make clear that there are no pre-agreements with any clubs," Sisic told Sky Sport Germany.

"For sure, a lot of top clubs have shown interest in him but Josko has a long-term contract in Leipzig.

"Josko feels totally happy in Leipzig. His development is amazing and RB is playing very well under Marco Rose."

Gvardiol has become a reliable figure for Zlatko Dalic in Qatar, ranking second among Croatia players for successful passes (281) and joint-third for tackles won (three).

No player managed more than the Leipzig defender's eight clearances and two interceptions in the round-of-16 clash with Japan in yet another astute performance.

Croatia team-mate Borna Barisic believes Gvardiol displays experience that belies his age, stating he has "everything in football".

"Josko is an amazing player. I think you can see that when he plays. He plays like he has 100 caps for the national team," Barisic said after the Japan triumph.

"That's [what happens] when God gives you everything in football. That's what he has. I think he will have an absolutely amazing career. He's a top player and a top guy.

"Sometimes when I'm looking at him, when he speaks before the game or in training also, it's like it's just some game without any pressure, like he's playing with some friends.

"He's very, very relaxed, but that's coming from confidence. He has crazy confidence because he knows how good he is."