Real Madrid and Atlético could be set for a transfer tug-of-war. Both are firm admirers of Chelsea's Marcos Alonso and, with the left-back potentially available for a fee of around 30m euros despite being a stand-out Premier League performer, he is shaping up as an eminently affordable option for the LaLiga pair.
Real youth product Alonso offers both defensive and attacking ability
Named in last season's PFA Premier League Team of the Year, the Spaniard has carried his 2017/18 form into the new campaign, and this weekend scored Chelsea's winner in a 3-2 thriller against Arsenal - showcasing the fact that, in addition to his defensive dependability, he also brings much to his side in attack.
Alonso is a graduate of Real's youth academy and, as is the case of many players who come up through the ranks of 'La Fábrica', the 27-year-old was forced to seek his fortune elsewhere. Following a stint at Bolton Wanderers, a successful spell at Fiorentina earned him a 30m-euro move to Stamford Bridge in 2016. Since then, Real and Atlético have both been keeping close tabs on him.
Filipe Luis, Theo see capital pair turn attentions to Alonso
Atleti had not been planning on moving for Alonso this summer, but Filipe Luis' potential departure for Paris Saint-Germain has opened up the possibility of replacing the Brazilian with the Chelsea man. At the Bernabéu, meanwhile, Theo Hernández's exit on loan has led Real chiefs to set their sights on the Spain cap, who worked with Los Blancos' new coach, Julen Lopetegui, in the club's youth set-up.
The Premier League transfer window closed on 9 August, meaning that English top-flight clubs are no longer allowed to make signings - but can still sell to teams abroad, so Real and Atlético could yet snap him up before the end of the month.
Versatility makes Alonso appealing option for Real
Alonso could therefore prove to be one of the major surprises of the final days of the window. Atlético had considered their summer business to be complete, but if Filipe does leave, he is the choice. Meanwhile, Real need a centre-back (in addition to a midfielder and striker) - and, as well as offering high-grade back-up to left-back Marcelo, central defence is a position where Alonso could also operate.
If he doesn't leave West London this summer, Real Madrid and Atlético can be expected to continue to vie for his signature in future windows.