Up to 27 players are close to being suspended for one Premier League.
The affected players have accumulated four yellow cards already.
A fifth booking will automatically trigger a one-match ban.
Already, Manchester City travelled to Aston Villa without Rodri and Jack Grealish, who picked up their fifth yellow cards during the 3-3 draw with Tottenham on Sunday.
Those who collected five yellow cards in the first half of the season will miss one match.
It is now 14 fixtures in and the likes of Kai Havertz and Bruno Fernandes will be desperate to avoid another costly booking.
Here are all the players who have been shown four yellow cards:
Kai Havertz ( Arsenal )
Matty Cash (Aston Villa)
Lucas Digne (Aston Villa)
Douglas Luiz (Aston Villa)
Kristoffer Ajer (Brentford)
Lewis Dunk (Brighton)
Enzo Fernandez (Chelsea)
Raheem Sterling (Chelsea)
Jordan Ayew ( Crystal Palace )
Jarrad Branthwaite ( Everton )
Abdoulaye Doucoure (Everton)
Ashley Young (Everton)
Antonee Robinson ( Fulham )
Issa Kabore (Luton)
Tom Lockyer (Luton)
Marvelous Nakamba (Luton)
Bruno Fernandes ( Manchester United )
Sean Longstaff (Newcastle)
Kieran Trippier (Newcastle)
Orel Mangala ( Nottingham Forest )
Ibrahim Sangare (Nottingham Forest)
Anel Ahmedhodzic (Sheffield United)
Oliver Norwood (Sheffield United)
Jack Robinson (Sheffield United)
Destiny Udogie (Tottenham)
Rayan Ait-Nouri ( Wolves )
Hwang Hee-chan (Wolves)
