Cesc Fabregas tops WhoScored's list of debuts from the weekend but you might also be surprised to see Patrick van Aanholt and Andrew Robertson in there...
We could have done practically a whole quiz on Chelsea's loanees but instead we've gone for the traditional one question per club...
Mourinho should make Chelsea genuine title challengers again
It goes without saying that, in terms of being restored to the title race, Mourinho's return would be excellent news for Chelsea. The Blues have struggled to remain a force at the top of the Premier League in the past three seasons, finishing a distant second in 2010/11 with only 71 points (four fewer than the current campaign), dropping to sixth last year and securing third on the final day of this season. Since his appointment at Porto in 2002, Mourinho has never managed a team to a league finish outside the top two, winning seven titles in four countries, two Champions League crowns and becoming the first manager ever to guide an Italian team to the Treble. It's fair to say that he guarantees short-term success.
Although Chelsea don't attract many neutral supporters, their return to the title race is also an attractive proposition for Premier League fans. Following a thrilling finale in 2011/12, the battle between the two Manchester clubs fell flat this year and a stronger Chelsea would add more tension and more excitement. It seemed that the top flight was set for a tedious duopoly similar to La Liga, but Mourinho's appointment at Stamford Bridge should ensure that all three clubs are vying for first place throughout the season.
He's enormously entertaining
This works both ways, with more on Mourinho being a self-indulgent, self-aggrandising [insert your own word here] later. In measured doses, it's difficult to deny that Mourinho's cult of personality provides an intriguing and entertaining subplot to the season. His arrogance can be enormously irritating, but character traits that provoke any type of reaction are better than the spoon-fed vapidity of another Paul Lambert or Chris Hughton.
Imagine Mourinho eye-gouging Sam Allardyce, riding the West Ham manager like a rodeo rider clinging onto a suited bull. With Mourinho there is always a chance of conflict, of something happening that breaks the norm. His antics can be infuriating, but initially his anticipated return will be a breath of fresh air.
He gets the best out of his players
Throughout his managerial career, Mourinho has been lauded by his players for helping them to improve and reach the peak of their ability. His coaching skills and the confidence he inspires in his squads have taken teams that had previously struggled under the weight of expectation to the next level, with Internazionale crowned champions of Europe for the first time in 45 years in 2010.
At Real Madrid, Mourinho has helped Cristiano Ronaldo develop even further and led the club to their first La Liga title in four years last season. This ability to eke the very best out of his players is good news for Chelsea fans and neutrals who are looking forward to seeing more of Eden Hazard, Juan Mata, Oscar and possibly Romelu Lukaku next season.
Mourinho has previously been accused of adopting a negative style of football, but Real Madrid have been hugely entertaining during his three-year reign and, if he can imbue the same standards at Chelsea, they should be an exciting team to watch.
He can resolve Terry and Lampard's futures
After a year of tedious stories about Frank Lampard's contract, as well as the midfielder's race to reach Bobby Tambling's goalscoring record, the last thing we want next season is more of the same. With the respect Mourinho commands - Lampard says he is 'the best' manager he's worked with - he should be able to resolve any issues over Lampard and Terry's contracts with the minimum amount of fuss and, hopefully, column inches.
It's quite disturbing how much he loves himself
As much as Mourinho is an entertaining character, the amount of self-love he exudes is both vomit-inducing and infuriating. The manager announced himself as 'The Special One' on his first arrival in England and, despite justifying the hype with back-to-back titles at Chelsea, his smug grin and braggart shtick gradually began to wear thin, like a holey old pair of pyjamas that reveal too many unpleasant glimpses of scrotum.
After Sir Alex Ferguson's retirement, the Premier League will benefit from the return of another big personality. But Mourinho's second spell at Chelsea will inevitably take a turn for the worse at some point and, as we have to listen to him blaming everyone else while he promotes his own interests, we may wonder why we ever looked forward to the Portuguese's return.
His time at Real Madrid ended on a sour note
Speaking of Mourinho blaming everyone else for his failures, the manager has spent the past six months doing exactly that as Real Madrid finished the season without winning any silverware of note.
Public spats with Pepe and Iker Casillas have undermined Mourinho's much-vaunted ability to create a tightly knit group who all want to do their very best for the manager and it seems that Real Madrid are happy to see the back of the Portuguese, allowing him to leave without any demands for compensation.
Mourinho's failings in La Liga, the Champions League and the Copa del Rey - in which Real lost to Atletico Madrid for the first time in almost 14 years - raise doubts over whether he will hit the ground running at Chelsea and instantly rediscover his spark. There is much planning and preparing to do at Stamford Bridge, but Mourinho may need time to reflect on where things went wrong in Madrid and how he can return to winning ways.
Chelsea improving will decrease top-four competition
If Chelsea take a significant step forward under Mourinho, as expected, not only will it increase the excitment of the title race, but it will also conversely affect the battle for the top four.
Chelsea's struggles in 2011/12 offered hope that Newcastle could break back into the Champions League places, while Spurs finished only three points behind the Blues this year. Of course, Chelsea were always likely to hold onto their position in the top three after Roman Abramovich's spending last summer - and the owner's anticipated investment in the coming months - but a move for Mourinho would seemingly cement their place in the top three.
This potentially leaves only one Champions League place up for grabs, as Arsenal, Spurs, Everton and Liverpool all watch the glass ceiling lowered another notch over their ambitions.
Been there, done that
Despite all the excitement over Mourinho's impending return, there is a sense that we've seen it all before. The first time the manager arrived he was fresh and new, and helped to reinvigorate the Premier League after seven seasons of Arsenal and Manchester United battling it out for the title.
But this time we already know everything about Mourinho. We know his pros, his cons, his tricks and mind games. Perhaps the manager's return will turn out to be a busted flush and he fails to settle at Chelsea after his previous acrimonious departure. Or maybe this will be one job too far after becoming disillusioned with life at Real Madrid.
We'll soon find out.
Matt Stanger - he's on the Twitter.