After scoring a career-best twenty-one goals during the season, Carlos was loaned for one year in July 1994 to Segunda División side CA Marbella.
After scoring eleven goals for Marbella, Carlos returned to Atleti in July 1995, and was subsequently assigned to the first team in La Liga the following January.
He made his top-tier debut on 6 January 1996, starting and scoring his team's first in a 3–1 home win against CD Tenerife.
Mainly a backup to Lyuboslav Penev and Kiko during his spell, Carlos was featured sparingly before moving to fellow league team Real Valladolid in 1997.
Carlos was an ever-present figure for the club during his two-season stint, achieving top tier promotion as champions but suffering immediate relegation.