Last February, Jones signed a new contract at Old Trafford to run until June 2023 and containing the option of a further year.
However, he has not featured in the Premier League since a 2-0 loss to Burnley at Old Trafford in January – a defeat that proved to be United's final reverse in the top flight in 2019-2020.
Romero has served as David de Gea's understudy since joining from Sampdoria in 2015 but has slipped down the pecking order since Dean Henderson's return from his successful loan stint at Sheffield United.
Jones and Romero were axed from Ole Gunnar Solskjaer's Champions League squad this month along with Marcos Rojo, although the Argentina defender has made the cut this time.
United has endured a mixed start to the Premier League season but bounced back from its humiliating 6-1 loss to Tottenham by beating Newcastle United 4-1 last time out.