The Carabao Cup may be regarded a lesser competition but there are still plenty of big teams in the quarter-finals.
Manchester United, Chelsea, Manchester City and Arsenal will be joined by Bournemouth, Bristol City, Leicester and West Ham.
But some passages through to the last-eight were easier than others.
United, Bristol City, Bournemouth, Leicester, Chelsea and West Ham all won their ties in 90 minutes but Arsenal and Man City needed extra-time and, in the case of Pep Guardiola’s side, penalties.
But it was during that additional 30 minutes that the two Premier League clubs may have breached Carabao Cup rules.
Carabao Cup rules
New laws state that the clubs are “permitted to use an additional substitute (in extra time only)."
“Each team is permitted up to seven substitutes of whom not more than three may take part in the match,” it says.
“Where any match goes to extra-time each club will be permitted to use an additional sub (in extra-time only).”
The rules are in place for teams to make a fourth sub if they have made their maximum of three during the match.
But Arsenal and City interpreted the rules slightly differently.
Arsenal made two changes during the 90 minutes and made an additional two changes during extra-time. Whereas City made one sub during the match and THREE during extra-time.
Is that allowed?
It seems not.
But will they be punished?
Norwich - who were defeated by Arsenal and Eddie Nketiah's goal in extra-time - were unsure if rules had been broken and were seeking clarification from the competition organisers.
“I think the rule has changed but it is complicated,” said Norwich boss Daniel Farke.
But, according to reports, both Arsenal and City won’t be disqualified from the competition or forced to play replays.
The confusion has arisen from a lack of clarity from the competition and clubs in previous rounds have also made the same mistake.
The Carabao Cup will no doubt look to clarify the rules ahead of next season.