Thompson said: "After the efforts which were put in at Old Trafford, it's particularly hurtful when you see comments coming from ex-players, notably Ian St John who was covering the game on Sky Sports, calling it the worst Liverpool season in living memory," said Gerard Houllier's assistant.
"I take great exception to that and so do the players. They're furious. It hurts. I certainly hope this is thing he may have said in the heat of the moment. But with the history of things Ian's said, I think not. There seems to be an ongoing thing Ian which has gone too far.
"I take no delight in speaking out about this but throughout our time here it's been well documented how Ian and certain other ex-players always seem to be on the other side, having a go at us."
"There was an article which appeared in a Scottish newspaper around the time of the Celtic match which was attributed to Ian and some of the comments he made were awful.
"We played two high class games against Celtic and in Glasgow we played some fantastic football. He described our performance at Anfield as 'gutless' but the final straw was when he said he wanted Martin O'Neill to enjoy the Anfield dug-out so much he'd want to be there more often.
"In those articles, he refers to Gerard as 'the Frenchman'. He can't even bring himself to call the Liverpool manager by his name. It's unfair and it's personal. Everyone can see that. I'm sorry that it has come to this, but we have to protect this football club and say how everyone is feeling.
"This has gone on for far too long now. I know how views can be presented, but with Ian it's all one way.
"What Ian should remember is from 1966-73 we never won a competition. He was part of that. He will remember he was a part of the team which lost to Watford in the FA Cup. That was a team which went down without a fight. That was a team I loved - a team which brought great honour and credit to the club over many years.
"Now he says we're the worst in living memory, even though we've won a cup competition, beating Manchester United in the final. The season isn't even over. We've still got a chance of getting in the Champions League.
"I don't want to make out for a minute everything in the garden has been rosy. But we were top of the league in November playing, contrary to what people said at the time, some great football. We should have had even more points because of the way we played.
"What upsets us all is there are certain ex-players who take great delight when it starts to go wrong. The newspapers and TV are suddenly full of certain people having a go.
"People might say 'what do you expect us to say' but I've been there myself. I know there is a fine balance about how you present yourself.
"No-one knows more than myself how important it is to be responsible and constructive when you're asked to comment on the club.
"I know I wouldn't be back in the position I am now if I had started kicking the club when it was down or taken the stance Ian and others have against the football club. I may not have been squeaky clean in everything I said or wrote, but I always tried to be dignified.
"I've been there, done it and know how things should be handled. You look at the likes of Kenny Dalglish, Ian Rush, Alan Hansen and John Aldridge who are continually in the media spotlight handling it so well. They remain as loved and respected by thefans as they've ever been.
"I'm not stupid. You don't want people to talk ignorantly or only ever say supportive things about the team and players. But what you come to expect is constructive criticism.
"This is not just a case of sour grapes after the weekend. It's been going on for a long time and there just comes a point when you think 'how long will we allow this to happen without defending ourselves?'
"I take no pleasure in bringing it up, but I know it's getting to the fans as well.
"We have a great relationship with the former players. They are welcomed with open arms. A lot of them, including Ian, are provided with complimentary tickets and hospitality.
"For all that's gone on over the past four years, we still open our doors for them. That's why it hurts greatly to hear the kind of comments we've seen and heard from Ian."