Stamford Bridge club go head-to-head with Bernabeu giants.
Chelsea manager Andre Villas-Boas will square off with former mentor and Real Madrid boss Jose Mourinho for FC Porto midfielder Fredy Guarin.
The 25-year-old has emerged, at £15million, as a cheaper alternative to Tottenham’s Luka Modric with the Blues on the hunt for a creative midfielder.
The Colombia international made 22 league appearances under Villas-Boas last year and helped the Portuguese club seal an historic treble, according to TalkSport.
Guarin can play in central midfield or on the right and scored five goals in Porto’s successful Europa League campaign – a strike rate which attracts the new Blues boss.
He played only 34 minutes of the Super Cup game against Vitoria Guimaraes and does not fit in with new Porto coach, Vitor Pereira, plans for the new season.
The former St Etienne player is not afraid to air his opinion and told of his frustration at making only 10 league starts via Twitter.
Meanwhile Manchester United legend Roy Keane has dismissed Chelsea’s chances of regaining their Premier League crown, saying they have a tendency to self-destruct.
“Everybody is on about this new young manager [Villas-Boas] – but I don’t think the manager will be the problem,” Keane told the Sun.
“It’s always the players down there, they all seem to self-destruct.
“They’re big pals one minute and the next you hear they’re all bickering with each other and players aren’t happy if someone else scores.”