The 32-year-old is out-of-contract in the summer and appears likely to leave the club he made his debut for some 14 years ago.
Ameobi was shown two-yellow cards in the space of ten seconds by referee Phil Dowd following Liverpool's second goal in their 2-1 win.
But as Newcastle were preparing to re-start the match, Ameobi was dismissed for dissent - the first red card of his career.
"You can't make up the way I was sent off. I still don't know why it happened," Ameobi told the club's website.
"I was given a first yellow card for dissent, but for the second one I'm ready to take the restart when the referee has called me back.
"He told me to stop showing dissent, so I told him that I was allowed to plead my case. I asked him 'are you going to send me off for trying to plead my case for my team?' and he said 'yes'.
"I've asked a question and been sent off for that. I'm dumbfounded by it.
"People who know me know I don't swear and that I am not abusive.
"If this is my last game for Newcastle then it isn't the way I would have liked to go out. I'm quite upset by it.
"If it is my last game, I wanted to go out on a high and we were doing great for an hour.
"I'm disappointed in myself for putting myself in that situation in the first place, but in the heat of the moment when decisions aren't going your way you get frustrated.
"I've apologised to my team-mates and would like to apologise to the fans because they were here cheering every single one of us on."