Sidnei has played at Deportivo during the last two campaigns. Getty

Valencia are considering a move for Deportivo de la Coruna centre-back Sidnei amid huge uncertainty surrounding their back-line, according to Marca. It comes as their Germany international Shkodran Mustafi is being heavily linked with a move to Arsenal, while the future of the other three centre-halves – Aymen Abdennour, Aderlan Santos and Ruben Vezo – is also in doubt.

The La Liga side have been forced into a huge clear-out during the current transfer window due to Financial Fair Pay rules. They have sold Andre Gomes to Barcelona and seen the departures of other players on big salaries such as Alvaro Negredo and Antonio Barragan, who have joined Middlesbrough, or new West Ham signing Sofiane Feghouli.

Manager Pako Ayestaran has said he hopes Mustafi, 24, does not follow them out the door, but sources suggest the club will not block his departure should a good offer arrive, as happened last summer when Manchester City signed Nicolas Otamendi in a big-money move despite Valencia insisting he was not for sale.

The departure of the Argentinian star left a gap in the Valencia defence they are still working to fill, with Abdennour and Santos, who were signed to help replace him, failing to make the expected impact and academy defender Ruben Vezo not convincing management that he is ready to make the step up.

The situation for Ayestaran could be even more concerning this season if Mustafi makes the expected move to Arsenal, stripping the manager of the only defender who performed well last term.

Arsene Wenger has admitted he needs a defender to replace injured Per Mertesacker before the end of the transfer window and Sky Germany reported that Mustafi is the likely candidate, with the Gunners having already opened talks to sign him in a deal worth around £25.3m ($33.4m) plus a further £8.4m in add-ons.

Asked on Sunday (31 July) whether he expects to sign the German defender, Wenger said: "We have not closed any deal with anybody at the moment. That's the answer. You speak about Mustafi. Is it Mustafi or anybody else? We haven't concluded anything at the moment."

Meanwhile, Valencia are preparing for the potential departure of his star. Napoli defender Raul Albiol and Fabian Schär, from Hoffenheim, have been linked with a move to eastern Spain in recent weeks, but Marca reports that Sidnei is now in pole position to join right-back Martin Montoya, who has just been signed from Barcelona.

The Brazilian Sidnei, 26, has been a crucial player for Deportivo during the last two seasons, following his move from Benfica.

Ayestaran knows him well from his time with the Portuguese club and, according to Marca, believes he would be a great addition to his problem defence. Mustafi's departure is almost certain as he is the only one of the existing defensive line-up who would command a decent fee.