Richarlison explained that he did not intend to hurt the Spain international while outlining why he believes what happened during the tackle, which took place in the 90th minute, was "inevitable".
The match was fraught with controversial moments but ended 2-2 after goals from Sadio Mane, Michael Keane, Mohamed Salah and Dominic Calvert-Lewin.
"Everyone who knows my background knows that I was never a violent player," Richarlison wrote on his website.
"What happened today was a casualty 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.
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"I already sent a message to him apologizing 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.