Ferguson claimed in his book Gerrard was "not a top, top player", even though he hailed him as the "natural successor" to Roy Keane nine years ago.
And Rodgers also leapt to the defence of Jordan Henderson, with the Northern Irishman describing Ferguson's less-publicised comments that the midfielder's running style as "inappropriate".
Less than a week after scoring his 100th Premier League goal at Newcastle, Gerrard was at the centre of attention again thanks to Ferguson's autobiography, much to Rodgers' chagrin.
"He (Ferguson) is probably one of the few - if the only one - who does not believe he is a top, top player," said Rodgers. I don't think it was credible really in terms of what was said.
"You only have to look at Steven's career since he has been here, the accolades he has received all his life not only from managers but former players.
"I saw something the other day which was interesting. There was a survey on the PFA player of the year and of all the players who have won that title, the one voted best among that was Steven Gerrard by all accounts.
"That was from players and supporters and there were some prestigious names on there.
"I think that Steven speaks for himself. He is a top player for sure: he may not have won the title but that is more because of the team he has been in rather than him himself.
"He is a world-class player and still operates at a high level."
In his book Ferguson said he was surprised Rodgers was appointed the successor to Kenny Dalglish at Liverpool last year.
The Reds boss was not bothered by that but took exception to his former United counterpart deconstructing Henderson.
"It is all about opinion. I'm not here to publicise his book, he's had enough coverage this week as it is," said Rodgers in relation to comments made about him.
"The one thing I would add is I was bitterly disappointed on Jordan Henderson.
"Sir Alex is someone who worked with and nurtured young players and so the statement in terms of Jordan was inappropriate really.
"He is a young player fighting for his career in the game. He is only 23 and looking to improve. He was outstanding at Sunderland but going to a big club was going to take him time.
"There was reference to his running style and his gait but every player is different.
"Everyone is medically assessed, you all have strengths and weaknesses, and over the course of their career the elements of their physical and technical qualities will be improved.
"I am sure somewhere along the line, if Sir Alex bumps into Jordan, he will apologise for that."