The market value and transfer fees of players depend on a lot of factors. Right from their playing ability to their marketablilty, a number of variables are taken into consideration.A player's potential and the number of years remaining in a contract also play a huge role. Young superstars like Kylian Mbappe and Erling Haaland could be on the move this summer with all the top clubs around Europe monitoring the situation closely.There has been some incredible rise and fall in market values as well recently. Neymar has struggled with form and injuries and with the Brazilian now 29, his market value has dipped quite a bit. Vinicius Jr, on the other hand, has seen an exponential rise in his market value after some great performances for Real Madrid this season.Without further ado, let us take a look at the 10 most valuable players in world football at the moment:(Market values from Transfermarkt)#10 Phil Foden (Manchester City) | €85 millionBrentford v Manchester City - Premier LeagueKnown as the 'Stockport Iniesta', Phil Foden has put in some remarkable performances for both Manchester City and England in 2021. One of the best players in the Premier League at the moment, Foden breaks into the top 10 most valuable players list for the first time, taking the place of Barcelona midfielder Frenkie de Jong.Phil Foden@PhilFodenGoal and three points… no better way to end the year! 💪🏻🔵04:42 AM · Dec 30, 2021420262348Goal and three points… no better way to end the year! 💪🏻🔵 https://t.co/3WClae1auuAn excellent passer and dribbler, Foden has been integral to Manchester City's dominance in the Premier League this season. The young Englishman has already contributed 5 goals and 3 assists so far.A versatile player capable of playing many positions across attacking midfield and the forward line, Foden will be hoping to build on his good performances and have an even better 2022.#9 Neymar (PSG) | €90 millionManchester City v Paris Saint-Germain: Group A - UEFA Champions LeagueIn March 2021, Neymar was second on this list and was worth €128 million. However, injuries and a loss of form has seen his market value drop more than €30 million in the last few months.One of the best players of this generation, Neymar is running out of time to really cement his legacy and win a Ballon d'Or award during his career. The Brazilian is still capable of magical things when he is in the mood.COPA90@Copa90The age-old debate: What exactly is a half-volley?Well, Neymar and Ander Herrera are here to demonstrate.5:30 PM · Dec 29, 20211476172The age-old debate: What exactly is a half-volley?Well, Neymar and Ander Herrera are here to demonstrate.https://t.co/iJiubad8wuNeymar was brilliant at this year's Copa America in Brazil and has shown glimpses of his genius for PSG as well. With Lionel Messi and Kylian Mbappe dominating all the headlines at the moment, the Brazilian superstar will be itching to get back into action and bamboozle opposition defenders once again.Also read to know Neymar's girlfriend, Carolina Dantas, and why they split?#8 Kevin De Bruyne (Manchester City) | €90 millionManchester City v Leicester City - Premier LeagueAnother player who has seen a slight dip in his market value is Manchester City's Kevin De Bruyne. One of the best midfielders of this generation, De Bruyne has also struggled with some niggling injuries this year.But whenever he has been fit, De Bruyne has put in some stunning performances for both club and country. A complete midfielder, De Bruyne's passing, throughballs and vision are all legendary.Manchester City@ManCityLovely bit of work from KDB 💫#ManCity | @Sure8:05 PM · Dec 30, 2021143599Lovely bit of work from KDB 💫#ManCity | @Sure https://t.co/b6Y1DgBQbeThe Belgian is arguably Manchester City's best player and Pep Guardiola will be hoping that De Bruyne remains fit and firing in 2022.