Manchester City, Tottenham Hotspur and Aston Villa face a headache registering the players they brought in during the January window.
UEFA rules stipulate that teams in the various competitions can only add a maximum three new players into their knockout stage squad from their league phase roster.
They all have a deadline of midnight on Thursday, February 6.
City were the Premier League’s biggest spenders, splashing £176.1m on four new faces.