Real made no secret of the fact that Carvalho was their top defensive target, but were ultimately outmuscled by Chelsea who - unlike their Spanish counterparts - did not baulk at Porto's near £20 million price tag.
As a result, Madrid seem to be channelling their efforts and finances into landing Arsenal skipper Patrick Vieira, but still want to add another centre back to their ranks.
Spanish daily AS claims that Los Merengues have already started negotiations with Milan for the services of Argentine stopper Coloccini - who can play centrally or at full back.
The 22-year-old has already proved himself in the Spanish game having spent the past three seasons on loan at Alaves, Atletico Madrid and Villarreal respectively, and impressing on each occasion.
Reports suggest that Milan, who already have Alessandro Nesta and Jaap Stam as their first-choice central defensive partnership, are ready to part with Coloccini for around £4 million.
Another option is Colombia captain Cordoba who currently plies his trade for Milan's city rivals Internazionale.
The 27-year-old, like Coloccini, has an EU passport despite his South American roots which is an important factor as Real have three 'foreign' players in their squad - Ronaldo, Roberto Carlos and Walter Samuel.
It remains to be seen which defender Real make a push for, although it seems their primary focus is securing Vieira.
