Right-back: Damian Suarez (Getafe)
La Liga currently lacks quality options in the right-back spot. Of all the available players, Damian Suarez has impressed the most. At 33, the Uruguayan has shown no signs of slowing down, making three assists for Getafe this season.
What he lacks in speed, Suarez makes up for with his attacking intent and brilliant link-up play.
Centre-back: David Garcia (Osasuna)
Osasuna are down to 14th place in the La Liga table. But they have conceded only 22 times so far, courtesy of David Garcia's talismanic displays.
His intelligent style of defending puts an emphasis on positional awareness. And combining that with an uncanny game-reading acumen has seen him stand out from a mediocre squad.
The 27-year-old averages a staggering 5.7 clearances per game in the league this season and another 1.5 interceptions. His aerial prowess is there for all to see too, winning 4.2 duels per game.
He has a knack for popping up with a goal or two every season but has netted thrice in the current one, which is already the most Garcia has ever managed in a single league campaign.
Centre-back: David Alaba (Real Madrid)
David Alaba has adjusted to life at Real Madrid very smoothly. The Austrian has taken no time to prove his worth to the side since joining from Bayern Munich on a free transfer.
His wealth of experience has been crucial to their defensive prowess this season, having conceded only 16 times from 19 games, the least in La Liga after only Sevilla (13).
Known for his leadership skills, aerial prowess, and set-piece ability, Alaba, still only 29, is the complete package. He could play a big part in Real Madrid's fortunes for many years to come.
Left-back: Jordi Alba (Barcelona)
Jordi Alba may be past his best but he's still continuing to remain of some value to Barcelona.
In the current league season, the left-back has registered four assists, the most for a player in his position in La Liga.
The Catalans are actively looking for a new recruit to strengthen the position. But if Alba can keep up his current form, then Barcelona may drop the idea of a new signing.