There's nothing worse for football fans than signing a player who's impressed elsewhere, but who fails to live up to their billing, or one who leaves your club after a disastrous spell only to excel after they've departed.
Manchester City have certainly had their fair share of players who fall into those categories, often lingering around picking up sizeable wage packets while the club struggled to offload them.
In fact, you could put together a decent XI of former City men who made a name for themselves in other clubs' colours. Here we select a side that frustrated in Blue and left full of regret.
Following in the footsteps of Peter Schmeichel, David Seaman moved to City with his best days firmly behind him. It was an embarrassing chapter in his Spunky's career, and one which ended prematurely and in failure.
He signed a one-year deal in the summer of 2003, but after a string of poor performances characterised by some absolute clangers, Seaman hung up his gloves and made way for David James to become City's No.1.
There's no doubting Seaman's credentials, having spent 13 years at Arsenal and winning 75 England caps, but his time at City was an unmitigated disaster.
During his days with Inter Milan, Maicon was generally considered to be the world's best right-back. He could attack like a winger and defend like, well, a defender, with his energy, strength and pace creating a perfect mix for a modern-day full-back.
However, at City, where he signed a two-year deal after his £3 million transfer from Inter, he struggled to make any kind of impact. Regularly injured and woeful when fit, he made just 13 appearances in all competitions before joining Roma for nothing.
Jerome Boateng is now a regular for the finest club side in Europe, but he struggled at City and failed to make any lasting impression.
He joined from Hamburg after impressing for the Bundesliga side, signing a five-year contract with City before setting off to play for Germany in the 2010 World Cup, where he shone. It all looked set to work perfectly, given his age and pedigree, but after a season in which he sustained a number of injuries, he joined Bayern Munich, where he continues to hold down a place in the first team.
City have had a few jittery centre-backs in the last 20 years, but none more so than Tal Ben Haim.
He was signed by Mark Hughes from Chelsea for a fee believed to be in the region of £5 million (via BBC Sport), but struggled badly from day one. In fact, it's difficult to remember a single decent performance. He lasted one year, including a loan spell at Sunderland, before joining Portsmouth permanently.
Poor signings were part-and-parcel of the Mark Hughes era at City, but Wayne Bridge has to rank as one of his very worst.
Like Ben Haim, he joined from Chelsea for £10 million and was seen as the long-term answer to City's left-back problem. He was reportedly earning £4.7 million-per-year but only made 58 appearances during his four-and-a-half year spell at the club, which included three loan moves subsidised by City.
Trevor Sinclair had established a reputation as a fine winger during his time at QPR and West Ham, but his performances for City had many struggling to see why.
A winger who struggles to take players on and lacks pace is pretty much useless, and that's exactly what Sinclair, a City fan in his youth, proved to be at the Etihad.
Owen Hargreaves spent seven years at Bayern Munich and had garnered a reputation as a fine defensive midfielder—one of the best in Europe. Manchester United paid £17 million for his services, but a series of injuries meant his time there was considered unsuccessful.
Despite his appalling injury record, Roberto Mancini inexplicably gave him a contract after he left Old Trafford, and he predictably found it difficult to stay fit and force his way into the side. He lasted just one season, making four appearances in all competitions.
He played 364 times for Liverpool during a nine-year spell, before moving to Real Madrid, where he won two La Liga titles and two Champions Leagues.
Keegan brought him to the Etihad in 2003, but he failed to produce anything like decent form. He played 44 times over two seasons, failing to score a single goal, and he was released in 2005.
Part of Sven-Goran Eriksson's exciting trolley dash around Europe prior to the 2007-08 season, Valeri Bojinov arrived from Fiorentina, having just spent a season on loan at Juventus. The excitement at his move was palpable, yet a wretched run of injuries saw him fail to make any kind of impact.
He made 12 appearances in two seasons, managing a solitary goal against Spurs, before departing for Parma.
Robbie Fowler is quite rightly considered one of the finest finishers in Premier League history, yet his time at City was defined by his lack of mobility and, more importantly, goals.
He signed for City from Leeds in January 2003, a move which was questioned by former chairman David Bernstein, but one which manager Kevin Keegan ws keen to conclude. It was clear almost immediately, though, that the instincts and sharpness that had defined his success at Liverpool had deserted him.
Fowler stayed for three years, making 80 league appearances and scoring 20 goals. He then moved back to Liverpool in what was one of the strangest transfers in recent history.
Another calamitous Hughes signing, Roque Santa Cruz spent a disastrous three years at City, making just 20 league appearances, scoring three goals.
He'd been a huge success at Blackburn, but it was clear for all to see that injuries were catching up with him and his best days were long gone, yet Hughes made it his mission to sign him.
City continually made their interest to Blackburn known, and eventually stumped up a £17.5 million fee, but three loan spells in three years and a free transfer move to Malaga in 2012 tell their own story.