Arsenal target £10 million Valladolid defender for January transfer (Cadena Ser)

Arsenal's increasing need to strengthen their defence in January has seen them target Real Valladolid defender Fernando Calero, according to reports in Spain.

The Gunners have lost Rob Holding to injury for the rest of the season, a knee injury during the recent 2-2 draw with Manchester United.

With Konstantinos Mavropanos also currently sidelined and club captain Laurent Koscielny yet to appear for the first team since rupruting his Achilles in May, Unai Emery is on the lookout for potential reinforcements in January.

And that has reportedly led them to 23-year-old Calero, impressing for a Valladolid side that have conceded just 15 times in 15 games in La Liga thus far this term.

Calero has also been linked with Sevilla and Bundesliga leaders Borussia Dortmund.

And the trio will need to move quickly, with Cadena Ser reporting that his contract contains a £10million release clause.

Arsenal have been playing with three centre-halves recently, and Holding's injury has meant full-back Stephan Lichtsteiner has been used out of position.

Nacho Monreal, a left-back, is likely to be asked to similarly deputise at Southampton, with both Sokratis and Shkodran Mustafi suspended for the trip to the south coast.

And, moving forwards, with the Gunners potentially fighting on four fronts come 2019 - assuming they beat Tottenham in their League Cup quarter-final -  pressure is on transfer chief Sven Mislintat to bolster Emery's ranks.