Longstaff watched Saturday’s 2-1 defeat to Watford from the bench after Steve Bruce, for the second game in a row, fielded defender Fabian Schar in midfield.
Bruce – who dropped on-loan midfielder Nabil Bentaleb following his poor performance against Manchester City at the Etihad Stadium three days earlier – had opted for Schar’s “physicality” over Longstaff’s athleticism at Vicarage Road.
Longstaff, needing minutes on the pitch following a recent lay-off, didn’t even get off the bench.
“I just thought we needed his physicality,” said United’s head coach. “His physicality was important to us. I think he did really well to be honest. It’s something we’ve done in training and worked on.”
The decision was questioned by some supporters in the wake of the result, and Bruce will face more questions over Longstaff between now and the end of the season given that he’ll be out of contract at the end of the month.
Newcastle have tabled an improved offer to the 20-year-old, and Bruce, for his part, has been trying to persuade Longstaff to stay at his boyhood club amid interest from Udinese.
United, it seems, have made their final offer, though the position of the club, waiting on a takeover decision from the Premier League, could yet change under new ownership.
“He’s a young lad, and wants to play football,” said Bruce. “There comes a time when he has to make up his mind. I’ve said many times the club has made him a wonderful offer.
“It was myself who gave him his debut, so I think he understands where we are with him. For me, it’s a football decision, but these days it’s the player's prerogative.”
But it’s not just about money to Longstaff.
Bruce has previously said Longstaff’s contractual situation won’t affect his selection.
Some fans are asking why Longstaff isn’t featuring more given how highly Bruce – who gave him his first-team chance in China last summer – says he rates him.
And playing him certainly won’t harm the club’s chances of keeping him.