Loan signings never really get as much attention as permanent ones do, and understandably so. Most players who leave a club on loan are either young, inexperienced or surplus to requirements.
But sometimes, loan moves also become the turning point of a player's career, who subsequently end up signing permanently for the new team, or return to succeed at the parent club.
They can either make or break a player's career. For example, David Beckham spent a brief spell at Preston North End in 1994. And then of course, there's Radamel Falcao, who had probably the worst loan spell of all time at Old Trafford (and then at Stamford Bridge).
Here, we take a look at 5 current on-loan players who are tearing it up at their respective clubs:
#5 James Rodriguez (Bayern Munich - on loan from Real Madrid)
Oh, how it could have turned out for James.
Having arrived in Madrid on the back of an incredibly successful World Cup campaign with Colombia, the fleet-footed playmaker never really made his mark in the Spanish capital.
Real's struggles this season, however, seem to indicate that his importance for the Spanish champions was perhaps underrated.
For James, himself, the loan move to Bayern seems to have been the right decision at this stage in his career. He's very much an integral part of a reinvented Bavarian side under Jupp Heynckes, having scored 2 goals and assisted 3 more in the Bundesliga.
He initially struggled for game time under his former Real Madrid boss Carlo Ancelotti. But following the Italian's sacking after the humiliation in Paris, and the appointment of cult hero Heynckes, he's become a first-team regular.
He's been utilised in both midfield and attack, and has performed consistently enough for Bayern to seriously consider making his move permanent.
If and when they decide to do so for €35.2 million, that price would be a bargain for James Rodriguez in this inflated market.
#4 Tammy Abraham (Swansea City - on loan from Chelsea)
Very few people knew who Tammy Abraham was last season. Just another product off of Chelsea's infamous assembly line of teenage loanees available on the cheap for second and third tier English clubs.
But 4 goals for a struggling Swansea City and an England call-up later, he's beginning to turn a few heads.
His superb return of 23 goals from 43 matches for Bristol City convinced the Swans to replace the departing Fernando Llorente by signing the 20-year-old on loan.
Antonio Conte recently hailed him as "a really good prospect for Chelsea's future." This bodes well for the youngster, who might well become one of those very few Chelsea youth stars who actually make it into the first team.
With Alvaro Morata and Eden Hazard being in incredible form, and with Batshuayi proving to be useful on more than one occasion, it does seem as though Tammy has his work cut out for him. But he's been doing the right things so far.
Certainly, one to keep an eye out for in the future.
#3 Henry Onyekuru (RSC Anderlecht - on loan from Everton)
The Nigerian winger was recently blasted by his manager for being too selfish, and his stats certainly reflect that. In 15 matches so far, he has 7 goals and no assists. But that is still a pretty impressive return for a winger who is still only 20.
Everton signed him in the summer after an incredible personal campaign in the Belgian top flight with Eupen, where he scored 22 times in 38 league games, finishing as the joint top scorer.
He was promptly sent out on loan to the reigning Belgian champions. But given his current form, and Everton's domestic and continental woes, the Toffees might be starting to regret sending him out.
His personal exploits haven't been able to rejuvenate Anderlecht though - they sit third in the Belgian league, trailing Club Brugge by 9 points.
His future certainly looks very bright - Manchester United and Barcelona have reportedly been scouting him. He has a few parts of his all-round game that he has to improve, including his passing and ball retaining, but if top clubs from England and Spain are keeping an eye on him, it is for a reason.
If he does live up to the potential that he has displayed in some of his performances so far, Everton might find themselves with an absolute gem on their hands, and considering that they signed him for a paltry £7 million, he could turn out to be quite a bargain in the long run.
#2 Kylian Mbappe (Paris Saint-Germain - on loan from AS Monaco)
The only reason the French superstar (yes, he's already a superstar) doesn't top this list, is because, for all practical purposes, he's already a Paris Saint-Germain player.
The French giants signed him from Monaco on loan with an obligation to buy, thus circumventing FFP regulations following Neymar's blockbuster move to the French capital.
The youngster has seemingly shrugged away any kind of pressure that comes with being the second most expensive player in the world. He's carried over his incredible form from last season which saw him lead Monaco to a Ligue 1 title, helping them end PSG's domination.
With 4 goals and 4 assists in the league, he's formed a formidable trio with Neymar and Cavani, with his adaptability enabling to play anywhere across a front three.
Whatever tension might exist between his two strike partners, he seems to get along well with both of them, and that's a very good sign for PSG. In terms of numbers, it might be the marquee names of Cavani and Neymar hogging the limelight, but Mbappe's performances indicate a maturity way beyond his age.
He won the Golden Boy award this year, and already has 10 caps for the French national team. His 3 goals and 3 assists in the UEFA Champions League also show that he's devastating against virtually any kind of opposition.
He's already broken the record for the most number of goals by a teenager in the UEFA Champions League, and the kid's not even 19 yet. He's a central figure for arguably the best team in Europe right now, and he's only going to keep improving.
#1 Goncalo Guedes (Valencia CF - on loan from Paris Saint-Germain)
Touted to be the next Ronaldo for the Portuguese national team, the 21-year-old winger has been a sensation at high flying Valencia.
For a club considered to be among the best in Spain, Valencia have had underwhelming 12th place finishes in the last couple of seasons.
This season, though, under new boss Marcelino, they've managed to stay within four points of leaders Barcelona, and are still undefeated in the league. They've already faced both, Barcelona, and Real Madrid, earning respectable draws against both of them.
One of the major reasons for their success is their slew of successful summer signings. Simone Zaza is second only to Messi in terms of league goals, and the trio of Geoffrey Kondogbia, Jeison Murillo and Goncalo Guedes have been instrumental in their good run of form.
Guedes has 5 goals and 3 assists in 11 league matches. While these numbers by themselves might not be extraordinary, the way he scored those goals were outrageous. His long-range finishing is surprisingly accurate, his mazy dribbling is a nightmare for any defender, and he has an eye for picking out decisive passes.
Having only signed for PSG in the winter of 2017, he immediately joined Valencia on loan in the summer window. It turned out to be the best move for both parties, with PSG being overburdened with an embarrassment of attacking riches, giving Guedes virtually no chance of making it into the starting XI (especially following Neymar's move).
With players like Julian Draxler and Angel Di Maria still facing a lot of times on the sidelines in Paris, Valencia might actually fancy their chances of snapping Guedes up next summer on a permanent deal.