Paul Pogba left Manchester United this summer, saying he wanted to show the club "they made a mistake".
The France midfielder, who is expected to rejoin Juventus on a free transfer, lifted the World Cup with his country in 2018 - but won only the Europa League and Carabao Cup at club level during his six-year second spell at Old Trafford.
His last three campaigns only produced eight goals.
But Pogba is far from being the only big name in Europe's major leagues with a point to prove this season.
From players who had disappointing loan spells to others who have barely played, who else really needs a big campaign?
Dele Alli has scored one Premier League goal since football was paused for the first coronavirus lockdown in March 2020
Dele Alli's stock has dropped dramatically in the past four years.
His first three seasons at Tottenham - as a teenager and in his early 20s - yielded 46 goals from midfield.
But instead of kicking on, he seemed to go backwards, only scoring 21 goals in the next three-and-a-half years - to the extent Spurs let him go to Everton without any upfront fee.
The change of scenery did not do Alli much good, though, and he failed to score in any of his 11 appearances - with only one start in half a season.
With the pressure off Everton after avoiding the drop, can the 26-year-old fare better for Frank Lampard's side this year? And who knows what is next for the one-time England international if he does not?
Donny van de Beek and Erik ten Hag are reunited at Old Trafford
It is hard to imagine a better managerial appointment at a better time for Donny van de Beek than Erik ten Hag's arrival at Manchester United.
The Dutch midfielder played 110 times for Ten Hag at Ajax, scoring 32 goals, before leaving for United.
But he only made four Premier League starts in almost a year and a half under Ole Gunnar Solskjaer before going on to a disappointing loan spell at Everton.
He would probably have been expected to leave Old Trafford this summer - but under Ten Hag, he has a big opportunity to become a key part of the team and prove Solskjaer wrong.
A loan spell is meant to help a youngster's career kick on but if anything it seems to have dented Scotland midfielder Billy Gilmour's reputation.
After 22 appearances as a teenager for Chelsea, many expected a loan stint at Norwich and a season of regular football to be the making of Gilmour.
But he only played in 60% of Norwich's Premier League games as they were relegated without much of a fight and he failed to score a goal.
Whether he stays at Chelsea or tries his luck elsewhere, it is a big season for the Scot.
Romleu Lukaku's second stint at Chelsea was a disappointment.
The Belgium striker was meant to be the missing piece in the Chelsea jigsaw when he joined from Inter Milan for £97.5m last summer.
He was clearly unhappy at Stamford Bridge and although he scored 15 goals, there was a feeling Chelsea were not playing to his strengths and he had spells out of the team altogether.
He is now back at Inter on loan and, although it was his choice to leave, he will want to show manager Thomas Tuchel what he could have had if he had built a team around him.
Marcus Rashford could really do with a big season at Manchester United to prove wrong those who claim his off-field work has got in the way of his football.
The 24-year-old made headlines in 2020 with his role in persuading the government to provide free school meal vouchers to pupils in the summer holidays.
He won book of the year at the British Book Awards this year for You Are A Champion, which was written to inspire young people.
But Rashford only managed five goals in all competitions last season - none since January - and was left out of the England squad for their Nations League games this summer.
Rashford must have a strong start to the season if he is show he should be part of the Three Lions squad for the World Cup in Qatar this winter.
Dean Henderson had to watch on as David de Gea played all 38 Premier League games last season
Manchester United goalkeeper Dean Henderson is another who has about three months to play himself into England's World Cup squad after joining Nottingham Forest on loan.
At the end of 2020-21, he appeared to have overtaken David de Gea to become United's first-choice keeper - and was named in England's Euro 2020 squad, although he had to pull out through injury.
That came after three full seasons of football during loan spells with Shrewsbury and Sheffield United.
But last season he did not make a single Premier League appearance, only featuring in three cup games, and has yet to add to his single England cap.
Too good for the Championship, not good enough for the Premier League?
For the third time in five years, Aleksandar Mitrovic and Fulham come up to the Premier League looking to emulate their Championship form.
In 2018-19, the Serb scored 11 Premier League goals. In 2020-21, it was just three.
But last season was his best Championship campaign by far, with a record 43 goals in 44 games. Is this the season he finally cracks the top flight?
Jesse Lingard will be desperate to show Manchester United they should have given him more of a chance last season - when he finds a new club.
The 29-year-old's career seemed to be petering out until he joined West Ham on loan 18 months ago. He netted nine goals in 16 games and won Premier League player and goal of the month in April 2021.
He returned to Old Trafford high on confidence last summer - and scored twice off the bench in September - but then only made four starts all season in all competitions.
Manchester United would not sell him in January to Tottenham, Newcastle or West Ham - but still never gave him a proper run in the team.
He left Old Trafford at the end of his contract and is now mulling over several options.