Everton forward Richarlison has attempted to defend his tackle on Liverpool midfielder Thiago Alcantara, putting it down to "over-dedication" on his part.
The Brazil international was issued a straight red card late on in Saturday's 2-2 draw at Goodison Park after catching his opponent close to the knee.
Jurgen Klopp could not reveal the extent of the injury when speaking after the Merseyside derby, but Richarlison was widely condemned for the strong challenge.
The 23-year-old issued an apology to Thiago on Saturday evening before later deleting the post, seemingly amid further backlash from rival supporters.
"Everyone who knows my background knows that I was never a violent player," he wrote. "What happened today was a fatality from sheer over-dedication. I did not enter that dispute with the intention of hurting Thiago.
"When I saw that the crash was going to happen, I picked up my foot and hit him with my knee in the pass, which was inevitable due to the speed of the play.
"I already sent a message to him apologising and I also do it here publicly. I hope he hasn't been hurt and that everything is fine. I also apologise to my teammates, my club and my fans for leaving them with one less at the end of the game.
"Unfortunately, there is nothing I can do to change what happened, other than to reflect, work and move on."
Liverpool are also awaiting the results of a scan for Virgil van Dijk, who suffered a potential anterior cruciate ligament injury following a poor tackle from Jordan Pickford.