Manchester United are still one of the world's biggest clubs, despite not winning the Premier League for five years. After 26 years of Sir Alex Ferguson at the helm, it was always going to be a period of transition.
Nevertheless, the list of players who regret leaving the Red Devils could still fill several books, particularly forwards. These players range from talents full of youthful promise who drifted into obscurity to experienced players who left for pastures new who found out that the grass was not greener on the other side.
However, it is easy to see why the players left the club, perhaps for the promise of a lucrative payoff or regular playing time after being consigned to the bench at United. But money isn't everything in football and spending time on the bench as a striker isn't always such a bad thing.
Take Ole Gunnar Solskjaer, who spent 11 years at the club, mostly appearing as a substitute, but who still managed to amass 126 goals. But these players found it hard to find the same rhythm after leaving.
#1 Dimitar Berbatov
The languid striker has been an enigma throughout his footballing career: he has long been much maligned for his 'lazy' playing style, although he is equally adept at playing majestic passes and scoring brilliant goals as he is infuriating fans with his less than obvious commitment.
Somewhat typically, throughout his time at United, he frustrated and delighted in equal measure, although he always had a regular starting place. Berbatov was bought from Spurs in 2008, where he had a very successful period and scored a lot of goals.
He was initially a great success at United, even if his price tag was somewhat limiting. Towards the end of his time at United, he got left out in favour of Wayne Rooney and the more energetic Javier Hernandez. And when he left the club for Fulham in 2012, things were never quite the same for the slender Bulgarian.
At Fulham, he was the main man but his scoring rate declined and he got even 'lazier', which pushed him out of favour, amid accusations that he was itching for a move, which he eventually got two years later to Monaco.
That was where he eventually faded into obscurity but the best years of his career were definitely at Spurs and United.
#2 Carlos Tevez
Prior to entering the Theatre Of Dreams, Argentinian striker Carlos Tevez had a reputation for being a divisive character who was always hankering for a move after a couple of years at a club, as he proved - somewhat justifiably - after being ignored for some of his time at West Ham under Alan Pardew.
However, that attitude was invariably matched by his considerable scoring ability and tenacious attitude throughout games. It was very much a case of taking the rough with the smooth.
So it proved at United, where he scored several goals amid a series of arguments, which was never going to sit well with the great Sir Alex Ferguson. But after making United's front-line feared again, he ultimately left the club in 2009 for neighbours Manchester City, which spawned the infamous 'Welcome to Manchester' poster.
At City, similar events occurred where he went on an extraordinary sabbatical after a row with boss Roberto Mancini and basically engineered a move away from the club.
At that stage, he was more known for playing golf than football and was left out of the Argentinian squad as a result. A move to Juventus and then his native Argentina followed, but it is very unlikely Tevez will ever recapture the glory he had at United where he won six trophies.
#3 Andy Cole
As a striker, Andy Cole was prolific for most of his career - until he left United. At Old trafford, he was arguably at the zenith of his career, averaging more than a goal every two games he played for the club in his six-year tenure and forming an almost telepathic relationship with Dwight Yorke during the club's treble-winning season.
However, Cole was known to be quite an introverted character at United who didn't really get on with his striking partners apart from Yorke.
Cole ultimately left United in 2001 for Blackburn Rovers - a move that started a slow move further down the league pyramid, playing for a myriad of lesser-renowned clubs like Portsmouth and Fulham.
He was never really in the first team at these clubs and his league career culminated in a torrid spell at home-town team Nottingham Forest, where he didn't even manage a goal.
Cole did very well during his career, but he definitely went downhill after exiting the Red Devils.
#4 Ruud van Nistelrooy
The Dutch striker was really in his element at United and produced numerous great displays over the five years that he was there, plundering a hatful of goals - 150 in 219 appearances to be exact. That is a phenomenal scoring rate, especially after he suffered what would normally be classed as a career-threatening injury.
However, after falling out with Sir Alex Ferguson due to poor form and his criticisms over fledgeling superstar Cristiano Ronaldo, he left in 2006 for Real Madrid. Sadly, he never really recaptured the heights that he hit at United with his other clubs.
At Madrid, he was in and out of the team and his scoring rate gradually declined and he missed out on being in the Netherlands squad on a regular basis. Eventually, he wound his career down with comparative minnows Hamburg and Malaga.
Van Nistelrooy himself admitted his behaviour had been unacceptable in his latter years at United, even ringing Ferguson to apologise - a tale he recounted in his autobiography. And frankly, Van Nistelrooy is right to have regrets,
If he had stayed at United, he could have become the all-time top goal scorer, the mantle of which was instead taken by Wayne Rooney.
#5 Wayne Rooney
It seems strange to include Wayne Rooney on this list but comparing his career at Manchester United to when he left the Red Devils shows the reasons why.
Even though Rooney has always split opinion among football fans and United fans as well, he achieved some very impressive things throughout his career at the Reds, particularly after he was let out of the shadow of Ronaldo and was allowed to become the club's main man.
As well as becoming United's all-time top goalscorer with 253 goals and winning every single major honour in the game, he also collected five Premier League titles.
Admittedly, towards the end of his time of United, specifically his final couple of seasons (2015/16 and 2016/17) it was clear Rooney was in decline as he put on weight and lost the explosive pace he used to have.
Nevertheless, since leaving the Reds, his powers have declined still further. After a solitary season at Everton (where he was still the club's top goalscorer with a paltry return of 11 goals), he is now seeing out his career in the MLS, just as David Beckham, Frank Lampard, and Steven Gerrard did before him.
He could have potentially stayed at United even longer and been a useful asset, given the club's current over-reliance on Romelu Lukaku but his fitness issues also saw him suffer towards the end of his United career.