Chelsea and Real Madrid "have already put in bids" for RB Leipzig centre-back Josko Gvardiol, according to Italian journalist Gianluca Di Marzio.
The 20-year-old has been in strong form for Croatia at the 2022 World Cup, making six appearances at the competition, with the European nation reaching the semi-finals of the competition before losing to Argentina.
Gvardiol also made a strong start to the season for Leipzig, featuring on 19 occasions in all competitions, with 13 of those coming in the Bundesliga and four in the group stage of the Champions League.
However, according to Di Marzio, the strongest interest is currently arriving from Chelsea and Real Madrid, with the duo already placing bids on the table.
The journalist claims that Chelsea are keen to sign the youngster in January, while Real Madrid want to wait until the end of the season to bring him to Bernabeu.
"I know Chelsea and Real Madrid are most interested in him at the moment. They have already put in bids, but his transfer value has skyrocketed due to his World Cup performance," Di Marzio told SoccerNews.
"Chelsea will probably make an attempt in January, but Real Madrid prefer a summer deal. I think Madrid would be the best for his career.
"Not only because we are talking about Real Madrid, but also because of the presence of Carlo Ancelotti, and he can make him better. Ancelotti knows a lot about defending and Gvardiol would benefit from the help of an Italian coach at this stage of his career.
"All top clubs are fighting for Gvardiol's signature, but in Croatian football the level of defenders is very high anyway."
Gvardiol's agent Marjan Sisic recently said that his client is "totally happy" at Leipzig amid the transfer speculation.
"Regarding a possible transfer in summer 2023 we are not in a hurry and I can make clear that there are no pre-agreements with any clubs," German journalist Florian Plettenberg quotes Sisic as saying.
"For sure, a lot of top clubs have informed about him but Josko has a long-term contract in Leipzig. Josko feels totally happy in Leipzig. His development is amazing and RB [Leipzig] is playing very good under Marco Rose."
Gvardiol made the move to Leipzig from Dinamo Zagreb in July 2021, and he has represented his current side on 65 occasions in all competitions, contributing three goals and four assists in the process.