The 28-year-old made his first appearance for his boyhood club in 20 months on Saturday, and insiders at Carrington say he has fully embraced what could have been an awkward reintegration, working relentlessly in training.
Barcelona declined to trigger a £26million option to sign him permanently despite a productive loan spell in Catalonia, and while interest from elsewhere in Europe has surfaced, no move has yet materialised. More than a fortnight remains before the window closes, but the likelihood of Rashford staying in Manchester increases by the day.
Manager Michael Carrick, who played alongside Rashford earlier in his Manchester United career, held a lengthy conversation with the forward ahead of his return.
Rashford rejoined his team-mates on 9 August and was introduced to the sizeable number of new staff who have arrived at the club since he was last a regular presence, as well as the training ground's new £50million facilities.
He has also taken a keen interest in helping develop the club's younger players, particularly 15-year-old prodigy JJ Gabriel, and has spent time with 19-year-old winger Shea Lacey.
Rashford has reconnected with England team-mate Kobbie Mainoo, while his time on loan at Aston Villa has left him close to Youri Tielemans, who joined United from Villa's fellow Birmingham club earlier this summer.
"It's clear to see that he is making a conscious effort to make the right second impression," one observer at the club told the Daily Mail.
Support for Rashford's return has also come from within the dressing room. Harry Maguire backed him to stay after United's pre-season concluded with a 4-2 defeat by AC Milan in Poland.
"He's a huge threat to have in your team, if he's going to stay with us," Maguire said. "Obviously the transfer window is still open, but we hope as players that he stays and he's a big asset to have.
"I've played with Marcus for numerous years and I know that from playing against him, and playing with him in training, he is going to help us."