The Paris Saint-Germain attacker was invited to train with Real back in 2006 and watched a match from the president's box at the Santiago Bernabeu. However, it was Barça who would snatch him up seven years later, following his return to Santos.
The Brazil international spent four years with Madrid's rivals, helping them win two La Liga titles and the Champions League before moving to PSG last summer for a world-record fee of £198m.
To this day, the player continues to be linked with Madrid. However, a summer of speculation ended anti-climactically with the Brazilian staying put in the French capital as the Ligue 1 champions refused to sell.
Carvajal, meanwhile, has spent most of his career with the Bernabeu residents, moving to Bayer Leverkusen in 2012 before returning a year later following the triggering of a buy-back clause. The Spaniard says he wants to finish his career at Madrid but is also tempted to experience playing in the Premier League.
"I do think about it," the defender said in reply to being asked if he considers playing abroad again. "And I am clear that I want to play in the Premier League. It is an experience that I really want to have.
"I don't want to be left wondering what it would be like. But, on the other hand, I would like to spend my whole career here, which would be something very nice, too."