Chelsea named their 25-man squad for the Champions League group phase on Wednesday, and some absences from the 'A list' of players may have raised eyebrows among some supporters.
Wonderkids Mason Mount, Callum Hudson-Odoi, Billy Gilmour, and Reece James haven't been included.
However, there is no need for fans to panic, as none of the quartet need to be included on the 'A list' because they qualify to be included on the Blues 'B list', which is reserved for young, club-trained players.
UEFA rules state that clubs must submit two lists of players for their Champions League registration.
The first one, List A, is the squad list that was submitted this week and contains a number of rules.
These include having a minimum of eight places for locally trained players - although the maximum number of players in their squad is reduced should these numbers not be met.
Locally trained means players that have been trained by their club or another club in the same nation for at least three years between the age of 15 and 21.
Four of these players must have been trained at the club they are being registered for.
Younger players, however, do not need to be registered on List A.
Instead, there is a List B for players born in 1999 or after who have been eligible to play for their club for at least two years since their 15th birthday.
There are no limits to the amount of players that can be registered on a List B, provided they meet the eligibility criteria for who is eligible for the B List.
That means Hudson-Odoi, who was born in 2001 and has been at Chelsea since 2017, as well as the likes of James (born in 1999), Mount (born in 1999), and Gilmour (born in 2001) are all eligible to be named on Chelsea's 'B list' of players.
Chelsea's 'A list' Champions League squad
Goalkeepers: Kepa Arrizabalaga, Willy Caballero, Edouard Mendy
Defenders: Antonio Rudiger, Marcos Alonso, Andreas Christensen (club-trained), Thiago Silva, Fikayo Tomori (club-trained), Kurt Zouma, Ben Chilwell (association-trained), Cesar Azpilicueta, Emerson Palmieri
Midfielders: Jorginho, N’Golo Kante, Mateo Kovacic, Hakim Ziyech, Kai Havertz
Forwards: Tammy Abraham (club-trained), Christian Pulisic, Timo Werner, Olivier Giroud,
LIST B: Mason Mount, Callum Hudson-Odoi, Billy Gilmour, Reece James, Karlo Ziger, Ian Maatsen, Henry Lawrence.
