Grimsby have been fined by the EFL for fielding an ineligible player in their shock Carabao Cup victory over Manchester United last week.

The Mariners beat United 12-11 in a penalty shoot-out, having led 2-0 in normal time before being pegged back.

The EFL said the breach related to Clarke Oduor, who came on as a 73rd-minute substitute.

The player’s registration was submitted at 12.01pm on the day before the match, shortly after the 12pm deadline required in accordance with this season’s competition rules.

EFL Statement: Grimsby Town fined after fielding ineligible player

📘 https://t.co/0DAEKxMLAC#EFL pic.twitter.com/j9TY1F96nD

— EFL Communications (@EFL_Comms) September 2, 2025

The League Two club have been fined £20,000, with £10,000 suspended until the end of the season which would be triggered if they fielded an ineligible player in any EFL competition.

The EFL said Grimsby self-reported the breach once they discovered the error the day after the match.

The EFL said the issuing of a fine followed precedent following a comprehensive review of all the evidence and considering prior decisions in respect of offences in the League Cup.

The EFL’s board determined the club’s non-compliance was not deliberate, with no intention to deceive or mislead.

In 2023, Barnsley were kicked out of the FA Cup after fielding an ineligible player in a first-round replay against Horsham.