But what exactly could their new line-up look like if they were to get all their transfer targets?
The Red Devils have been linked with a number of high calibre players of that they could bring to Old Trafford this window.
But given Paul Pogba, Edinson Cavani, Lee Grant, Jesse Lingard, Juan Mata and Nemanja Matic have all left, United's squad is guaranteed to look totally different come August, regardless.
So who are United targeting? And what could their ultimate starting XI be?
Here's how the Red Devils could line up on the opening day of the Premier League should they recruit those on their wanted list.
Given ten Hag is renowned for playing 4-3-3, it's likely he'll set his first United team up in this way.
Current players Cristiano Ronaldo, David de Gea, Jadon Sancho and Luke Shaw are likely to remain in the XI.
After failing to land Liverpool new signing Darwin Nunez to assist Ronaldo up front, it's understood United could be scouting out a right winger to bring in another option for starlet Antony Elanga instead.
Given last summer's signing Jadon Sancho is now deployed on the left wing instead, United do need to invest in this area.
It's no surprise then that Elanga's namesake Ajax winger Antony is on ten Hag's wish list, given the pair worked together at the Dutch club this season.
In a similar vein, another player that could feature in United's line up is Ajax centre-back Jurrien Timber.
After scoring three goals and recording two assists in 43 appearances last season under ten Hag, it's easy to see why the Red Devils boss would be keen to recruit him.
Steering away from players following the Dutchman to United from the Amsterdam, the Red Devils could also do with some more options at right-back.
It's unclear Aaron Wan-Bissaka will be in ten Hag's plans and Diogo Dalot could do with some back up.
And one target United have is Inter Milan wing-back Denzel Dumfries.
After being directly involved in nine league goals for Inter last season and scoring five, the Dutchman could be exactly what United need to get their offensive prowess back on track.
It's in the middle of the park that United will undoubtedly be focused on, though.
And it's free agent Christian Eriksen and Barcelona's Frenkie de Jong that ten Hag reportedly has his eyes on to solve his midfield woes.
Given long-standing midfielders Mata, Lingard and Pogba have left, it's vital United recruit well in this department and in-demand Eriksen and exciting de Jong are the type of players ten Hag will need.