The 21-year-old was in excellent form for Nottingham Forest during the 2021-22 campaign, scoring four times and providing 10 assists in 49 appearances, with the Reds securing a return to the Premier League.
Garner is due to link up with Man United at the start of July, and it has been suggested that Erik ten Hag will give him the chance to earn a first-team spot at Old Trafford next term.
The England Under-21s international has said that he is determined to impress during pre-season and convince Ten Hag to keep him in Manchester for the 2022-23 campaign.
"I'm not too sure (what will happen), personally. I've not had much time to think," Garner told reporters. "I've gone from Championship football straight to international football; I've not really had a breather or time to think.
"Well that's the plan (to impress Ten Hag). That's what I'd like to do; go on pre-season and impress, it's all up to me, really. It's down to me as a player to impress him and hopefully make a mark."
Garner is confident that his loan spell at Forest has helped him grow as a player, while he has also recently been involved for England Under-21s, playing three times for the national side earlier this month.
"It's huge (next season). I feel like last season my career has only just started, I'm still young, just turned 21 a couple of months ago. I've had such a good season this season, with the national team and at club level as well. As you said, it's very important now to hopefully play in the Premier League next season.
"I think I've come on leaps and bounds this season. Played a lot of games, 50-plus now, so I've developed a lot physically, which was the question I was asked - whether I'd be able to play, whether I'm ready physically. I think I've shown I'm physically ready to play and, like I said, felt like I've come on leaps and bounds.
"I just feel like, before I went on loan, there were questions of am I physically ready to compete, to play first-team football, and I believe that I've shown that this season. Not only playing a lot of games but how I've held my own in such a tough league and men's football, you know. I think I've shown that."
Garner also had loan spells at Watford and Forest during the 2020-21 campaign, while he has made seven first-team appearances for Man United, including two outings in the Premier League.
The Englishman came through the youth system at Old Trafford and was involved in their pre-season tour in the summer of 2018, while his first-team debut came in February 2019.
The 20-time English champions will take on Liverpool, Melbourne Victory, Crystal Palace, Aston Villa, Atletico Madrid and Rayo Vallecano in friendlies this summer.
Man United will first head to Thailand to face Liverpool before making the trip to Australia, while their final pre-season fixture will be against Rayo at Old Trafford on July 31. body check tags ::