The West London giants are desperate to land some marquee signings at the Stamford Bridge to increase the defensive options and save the season.
Guus Hiddink has already revealed new players will come.
As per the latest reports, Chelsea officials are eyeing the-18-year old goalkeeper Adrian Semper.
Semper, 18 impressed fans with his stunning performances and the excellent goalkeeping skills for Dinamo Zagreb and Croatia U21 team.
Despite Chelsea interest, Dinamo Zagreb officials rejected any speculations over his move.
“Chelsea representatives have been in Zagreb, where they have prepared a great offer,” Mamic said.
“They were professional and pleasant people, but we said no.”
“It is never easy to reject such a big offer for a young player, but we are convinced Adrian has a fantastic future ahead of him and we want him to spend at least some of that future with Dinamo.”