Maquillo has joined the club on loan and becomes the club's seventh summer signing.
Manquillo has been on the fringes of the first team of the La Liga Champions and Champions League runners-up but often found himself playing second fiddle to Juanfran.
On Merseyside he will be in competition with Glen Johnson and Jon Flanagan for the right-back spot in the side, as he adds depth to a Liverpool team preparing to compete on four fronts this season with the side entering the Champions League for the first time in five years.
At 20-years-old, he and Flanagan may be the long-term competitors for the right-back role with Glen Johnson entering the final year of his contract at Anfield.
Manquillo's versatility will have been an attraction to manager Brendan Rodgers having filled in on the left flank during his time at the Vicente Calderon.
It will be interesting to see how much of a role he has in the Liverpool side this season given the intense competition he is likely to face.
Here are a few pictures from the official Liverpool twitter page of the young Spaniard being unveiled as a Liverpool player at Melwood:
Liverpool FC (@LFC) August 6, 2014
Will Manquillo prove to be a good signing for Liverpool?