The challenge, which occurred during Palace's 2-1 victory over the Reds at Anfield on April 23, forced Tomkins out of action for three weeks.
In his absence, the Eagles were plunged into a relegation battle, losing to Tottenham Hotspur, Burnley and Manchester City, but he returned on Sunday to help retain the club's Premier League status with a 4-0 triumph over Hull City.
"The challenge was brushed under the carpet a bit," The Independent quotes Tomkins as saying. "I'm not one to complain about the physical aspects of the game and I accept opposing players are going to be competitive but I thought the tackle was disgusting really.
"I managed to get away with it because it could have been a lot worse. I worked very hard to get myself back to fitness and just wasn't quite ready for City last week but I was very happy to come in against Hull even though there's still a bit of pain."
Palace will end their season at Old Trafford, taking on Manchester United on the final day of the campaign this Sunday.