West Bromwich Albion and Swansea City may both be in need of defensive reinforcements in January.
Siovas only moved to Leganes on a permanent basis from Olympiacos last summer, following a successful spell on loan to the Liga side - who paid around £2.7 million for him, according to Transfermarkt.
And the Daily Mail reports he has a release clause of £10 million, which may have to be triggered if he is to be prised away in January.
Respective West Brom and Swansea defenders Jonny Evans and Alfie Mawson could be on the move this month, and losing them may prompt the pair to step up their pursuit of Siovas, who has kept five clean sheets in 10 league outings this season.
The 6ft 4in Greece international could have reservations about a move to either West Brom or Swansea, however, with both clubs adrift at the bottom of the Premier League.
Leganes, on the other hand, currently sit ninth in La Liga, and are only eight points worse off than Real Madrid.
Would West Brom / Swansea be a good move for Siovas?