United endured one of their worst-ever seasons in the 2024-25 campaign, finishing 15th in the Premier League with a club-low 42 points.
A bright spot was the club's run to the Europa League final, where they were ultimately defeated by Tottenham.
The Red Devils began their off-season with a brief trip to Asia, followed by a European friendly against Leeds.
Their U.S. tour has seen them face West Ham (2-1 win), Bournemouth (4-1 win), and Everton (2-2 draw), with a final friendly against Fiorentina at Old Trafford to come.
"I just want to be part of a successful team this season. I think last season was a tough season for everyone individually, but also as a team, as a squad, as a club," Maguire told MUTV.
"This season, there are no excuses. We're going to have a lot of time to prepare for the Premier League games, and we've got to make sure we're ready.
"So, for myself, it's making sure I'm available, I'm fit, I'm ready to go, and give everything I can to this team and this club.
"It's something that [Ruben Amorim] reiterated, that we didn't have enough time on the training pitch. This pre-season, it's been tough on the legs, but the majority of it has been tactical.
"So, it's nice to do the drills that are tactical rather than running around poles and running around the pitch. It's been an enjoyable pre-season, but a pre-season that we've all learnt from.
“We know the system a lot better, and we've just got to take that into the games now.”
Newcastle United have reportedly intensified their pursuit of RB Leipzig's star striker Benjamin Sesko, escalating a transfer saga that could reshape the Premier League's attacking landscape.
Manchester United are closely monitoring Gianluigi Donnarumma's situation at Paris Saint-Germain, with the Italian goalkeeper emerging as a serious long-term target for the club.
Manchester United captain Bruno Fernandes has called on his teammates to raise their standards as the club undergoes sweeping off-field changes.
Manchester United are reportedly planning a blockbuster raid for Barcelona midfielder Fermin Lopez with Sir Jim Ratcliffe willing to splash the cash to get his man.
