Source UEFA.com

We are in that stage of the European football season were top clubs from the top European leagues starts sending in their UCL list of eligible players to prosecute the group stage matches.

It is interesting to note that the governing body has an arrangement known as the 'B-List'.

Question is, what is a B-List? According to A Skysports Report, it explains that..

A player may be registered on the B List if he is born on, or after, 1 January 1998 and has been eligible to play for the club concerned for any uninterrupted period of two years since his 15th birthday (players aged 16 may be submitted if they have been registered with the club for the previous two years).

Clubs are entitled to register an unlimited number of players on the B list during the season, but the list must be submitted by no later than midnight the day before a match.

For example, the players most likely to benefit from the B-list ruling are Mason Greenwood of Man United. Curtis Jones and Neco Williams of Liverpool, etc.