Barcelona's option to sign Rashford permanently stands at £26 million and expires on June 15 — four days after the World Cup begins in North America.
The club attempted to negotiate a reduced fee and explored the possibility of a further loan, but United have rejected both proposals and are standing firm on their valuation.
Marca reports that Rashford has "completed a cycle" at the club alongside four others earmarked for the exit — Robert Lewandowski, Frenkie de Jong, Andreas Christensen and Marc Casado. Rashford contributed 12 goals and 13 assists across 43 appearances during the loan spell.
The 28-year-old joined Barcelona last summer having previously spent the second half of last season on loan at Aston Villa, where he scored four goals and provided six assists in 17 appearances.
He has not played for United since December 2024.
His return to Old Trafford would place whoever is in charge — Michael Carrick's contract also expires this summer — with a significant decision to make. United could reintegrate him into the squad or pursue a permanent sale to recoup funds.
Sources have previously indicated the club believes his Barcelona form has increased his market value and that a higher fee could be negotiated with another buyer.
Rashford has worked his way back into Thomas Tuchel's England plans and is expected to be part of the World Cup squad, which adds further urgency to resolving his club future before the tournament.