The 21-year-old midfielder made his first start of the new season for the Whites in their 3-0 Carabao Cup win over Crewe, but is likely to be back on the bench as the Elland Road team continue their Premier League campaign.
After being identified by head coach Marcelo Bielsa as one of the brightest talents to come out of the United academy in recent years he has been forced to bide his time to get a regular spot in the Argentine’s spell in charge.
But his regular inclusion as a substitute indicates he is close to getting in and the fact he is involved most weeks with the first team indicates his value to the club when other academy graduates from the same time as Shackleton have fallen by the wayside. It helps too that he can play more than one position as he has filled in at right-back as well as playing in midfield where he has played most of his junior football.
On being asked what his ambition for the 2021-22 season was, Shackleton said: “To be in the line-up, whether that is at right-back or central midfielder.
“I am going to give 110 per cent whenever I’m on the pitch.
“I think that is everyone’s aim in the squad. If you’re in the first-team squad then your aim is to be starting games and pushing for a spot. That’s ultimately what makes the whole team better.
“It’s definitely my aim to be in the line-up but it’s also everyone else’s in the squad as well.
“I’ve come off the bench a few times now. It’s something that I’ve done plenty of. It’s important to get up to speed quickly, you can’t be slowing the game down or making mistakes when the game is flowing and in a team playing at a high tempo.”
Shackleton added: “I think I’ve been in and around the first-team squad for three years now. I’m well aware of what is required in both positions because I’ve played both so I know about both.”