Chelsea have pitched into a bidding war for Bayern Munich star Toni Kroos as Jose Mourinho attempts to further toughen-up his midfield selection.

Kroos, who was one of the stars of a Germany side that humbled Portugal 4-0 in the World Cup's opening week, is said to be keen to leave the Allianz Arena this summer.

He has been heavily linked with a host of top European sides, including Barcelona and Real Madrid, but has ruled out a move to Blues' Premier League rivals Manchester United.

In action: Toni Kroos takes on Wayne Rooney

Earlier in the year he said: “I am expecting to play for Bayern Munich next season.

“There was a lot of speculation, but Manchester is and was not an issue."

However, Chelsea now appear to be favourites to sign the 24-year old, who is in the last year of his Bayern deal, and could move for around £15m.

Mourinho is also likely to be in the market for an additional centre half, with defender Kurt Zouma looking set for a campaign gathering Premier League experience with another season-long loan.

With David Luiz Having left the club, that leaves Chelsea with only John Terry, Gary Cahill and Branislav Ivanovic in central defence.

Tomas Kalas, who impressed for Blues at Anfield towards the end of last season, has been sent on loan to Bundesliga side FC Cologne.

Out on loan: Chelsea's Tomas Kalas

Chelsea, meanwhile, have added another pre-season friendly to their calendar  ahead of the Premier League opener at Burnley.

They will travel to Hungary to face Fenecvaros on Sunday 10 August.

Other friendlies have already been announced against Austrians RZ Pellets WAC, NK Olimpika Ljubljana of Slovenia, unofficial nursery club Vitesse Arnhem of the Netherlands and German outfit Werder Bremen – all away from home.