The Argentina international was expected to secure a permanent move away from the Tottenham Hotspur Stadium last summer, only to stay and try to prove his worth to Ange Postecoglou.
Lo Celso only momentarily succeeded in that regard, scoring two goals and setting up two more in 22 matches in the 2023-24 Premier League season, and he has not played once competitively so far this season.
As a result, the 28-year-old has inevitably been tipped to finally end his ill-fated North London stint this summer, and a return to Spain has been strongly mooted before the transfer window slams shut.
Real Betis are said to be working to bring Lo Celso back to La Liga after the midfielder's successful two years in green and white, where he managed 16 goals and six assists in 45 matches.
Tottenham 'not accepting' Betis' Lo Celso conditions
However, Fabrizio Romano reports that negotiations have stalled, as Tottenham are not satisfied with the conditions offered by their La Liga counterparts, leaving Lo Celso's future shrouded in uncertainty.
The 28-year-old only has one year left to run on his Tottenham contract, meaning that the Lilywhites cannot realistically demand a large sum for a sale, although they are keen to recoup a good chunk of the £26.9m they paid Betis for his signature in 2020.
Since touching down in North London, Lo Celso has managed 10 goals and eight assists in 108 matches for Spurs, but he is firmly behind James Maddison in the number 10 pecking order.
Lo Celso could also be offered the chance to stay in the Premier League with either Aston Villa or West Ham United, although it is currently unclear where his transfer preference lies.
Tottenham are back in Premier League action away to Newcastle United on Sunday afternoon, but Lo Celso is not expected to be part of Postecoglou's matchday squad at St James' Park.
What other players could Tottenham sell on deadline day?
Barring Lo Celso and a couple of others, Tottenham have either sold or loaned out most of the players who they planned to offload, including the contract termination of Tanguy Ndombele and free transfers of Ivan Perisic, Eric Dier, Ryan Sessegnon and Japhet Tanganga.
Postecoglou has also allowed Oliver Skipp, Troy Parrott, Joe Rodon and Emerson Royal to leave permanently, while Manor Solomon, Bryan Gil, Pierre-Emile Hojbjerg, Alejo Veliz, Ashley Phillips and Dane Scarlett have departed on temporary deals.
Lo Celso is one of two outcasts who could be on the move in the coming hours, though, a list that also includes Sergio Reguilon, who is back in North London following his loans with Brentford and Manchester United last season.
However, Tottenham are seemingly struggling to drum up interest in the Spaniard, who is arguably Postecoglou's fourth-choice left-back behind Destiny Udogie, Ben Davies and Micky van de Ven.
Richarlison was formerly linked with a move to Saudi Arabia too, but Dominic Solanke's recent ankle injury should scupper a potential move away for the Brazilian.