Liverpool won the away match against Manchester United in the Premier League (1–0), despite Gueye being sent off in the 13th minute.
The Senegalese got into an argument with teammate Michael Keane after a misunderstanding, which ended with Keane getting a slap in the face and Gueye receiving a red card.
In addition to the apology to Keane, Gueye targets his other teammates, the staff, supporters and the club.
"What happened does not reflect who I am or what I stand for. Emotions can take over but nothing justifies such behavior," he writes.
