The pair regularly indulged in mind games before their north-west derby clashes when Benitez was manager of United's arch rivals Liverpool and the digs have resumed since the Spaniard was appointed interim boss at Chelsea in November.
But with Benitez enduring a torrid time and hugely unpopular among Chelsea fans, prompting him into an extraordinary tirade against both them and the board last month, Ferguson has laid off the jibes before this weekend's Old Trafford encounter.
"I'm not going to kick anyone when they are lying down, it's not my style," the United manager told a news conference on Friday.
"My concern is as manager of Manchester United, whatever happens at Chelsea doesn't really affect me."
With United still reeling from Tuesday's Champions League exit at the hands of Real Madrid and the controversial red card for Nani that completely changed the game, Ferguson may not have been in the mood for any sniping.
"It's another competition and a different atmosphere, it will be totally different and another challenge for us," he told reporters.
The subdued build-up to the pick of the weekend's FA Cup Quarter-Finals is in contrast to previous exchanges between Ferguson and Benitez.
Ferguson, meanwhile, branded Benitez "lucky" last year for walking into the Chelsea job, saying it would be the second time he had the chance to win a world club title without having to do anything and with a team put together by someone else.
Benitez succeeded Jose Mourinho after Inter Milan's 2010 Champions League triumph but was sacked soon after their Club World Cup victory.
"We've got a healthy lead in the league which is a great position to be in, we can enjoy the cup on Sunday, that's the value of it, make it a really good day for ourselves," he said.
He said it was a tough fixture because of Chelsea's great record in the competition in recent years. The Londoners have won it four times in the last six seasons, including in 2007 when they beat United in the final.
