Stephens received a red card during the Premier League match against Manchester United earlier this season.
Jack Stephens, the Southampton defender, will face a two-game suspension extension.AdvertisementAdvertisementThe 30-year-old was dismissed for a high tackle on Alejandro Garnacho, which led to his team being down to ten men for a considerable time.
"I am well aware that what I said was completely unacceptable and below the standard of conduct expected of me," Stephens wrote in a letter to the FA Regulatory Commission.
"I am very embarrassed by my behaviour and want to apologise sincerely for it."
Southampton lost 3-1 to Bournemouth on Monday in Stephens' absence and have not yet won on their Premier League return.