On 13 June 2019, the UCI stated that Cobo had been found guilty of a doping violation, based on his biological passport data.

In 2004, Cobo became professional in the new Spanish team Saunier Duval–Prodir, led by Mauro Gianetti, manager of Vini Caldirola in 2003 .

In 2008, still with Saunier Duval, he made a quieter start to the season but finished second in the Tour de France Hautacam stage, behind his teammate Leonardo Piepoli.

Cobo stayed faithful, which allowed him to assume responsibility as a team leader, finishing 10th at the Vuelta a España where he also won a stage.

Especially fierce was the attack Froome produced in the last kilometer of the seventeenth stage, Cobo was dropped for some time before he rallied and made the juncture very shortly before the finish line.

[1] He had a year without victories, participating in the Tour de France and landing a 30th general classification placing.

He was slated to be his team's leader at the Vuelta a España to defend his title, but the leadership was soon shifted to Alejandro Valverde, after the latter performed better than Cobo in the early stages.