Madrid giants battle it out over Marcos Alonso

Alonso's strong form in recent years has seen him establish himself as one of the Premier League's best left-backs and it appears that his development has not gone unnoticed.

The Spain international shone in Chelsea's victory over Arsenal at the weekend, assisting Eden Hazard's opener and scoring the winner for the 'Blues' in a Man of the Match performance.

According to 'AS', such performances could be set to earn him a move to the Spanish capital, with both Real and Atletico monitoring him closely.

The Spanish transfer window remains open until August 31 and both clubs are looking for defensive reinforcements after Real's Theo Hernandez joined Real Sociedad on loan and with question marks remaining over the future of Filipe Luis at Atleti amid interest from PSG.

With Chelsea unable to sign a replacement and the player under contract until 2021, it would come as a major surprise were the club to allow Alonso to depart before the deadline.

Alonso is well known to Real, with the left-back having come through their academy some years ago. With Marcelo not getting any younger, many 'Los Blancos' fans see Alonso as the ideal replacement for the fan favourite.

The report suggests that a fee of €30m may be enough to tempt Chelsea to cash in on the player, with that seen as reasonable given the recent inflation in the transfer market.

However, with Chelsea reluctant to cash in now, there is a possibility that both sides could postpone their interest until January.