Sunderland are demanding a transfer fee for out-of-favour Santiago Vergini after rejecting a proposal from suitors Boca Juniors to sign the defender for free.
Vergini faces an uncertain future when he returns to Wearside at the end of next week after last season’s loan spell at relegated La Liga outfit Getafe failed to materialise into a permanent switch.
The Argentine international - sent out on loan by Allardyce’s predecessor Dick Advocaat - has been attracting interest, most notably from his homeland where Boca are understood to have made contact with Sunderland.
However, it is thought that Boca’s initial offer was to sign Vergini on a free transfer, which has been turned down by Sunderland.
While Vergini’s departure would free up a chunk of funds on the wage bill, Sunderland are keen to recoup some of their enforced investment in the 27-year-old from last summer.
Sunderland were duty-bound to sign Vergini for around £2million - despite Advocaat evidently not wanting the player back - after he had made more than 20 Premier League appearances in the previous season.
The Black Cats are confident they can cut some of their losses on a player, who has been capped by Argentina and made 24 starts in the Spanish top flight last year.
Boca are not the only party interested in Vergini, with Real Betis - now managed by ex-Sunderland boss Gus Poyet - strongly tipped to take him back to Spain.
Any concrete confirmation of Betis’ interest is yet to emerge, but Poyet first brought to Vergini to the Stadium of Light and was desperate to re-sign him on a second occasion after his initial loan spell.
However, Sunderland are under pressure to offload Vergini and half-a-dozen of his team-mates - Emanuele Giaccherini, Charis Mavrias, Will Buckley, Liam Bridcutt, Jordi Gomez and Adam Matthews - who will return to the Stadium of Light after loan spells elsewhere.
None have a future at Sunderland, with Allardyce needing to offload them to bring down the cost of a wage bill which was the 10th highest in the Premier League last season.