Ferguson and Benitez have been at loggerheads this season over the transfer saga involving Heinze.
"I want to be clear. I have a lot of respect for Sir Alex Ferguson, because he is a great manager," Benitez told the Sunday Mirror .
"But I have to think about my club and maybe now we have a better squad he knows we can become contenders.
"It is good people are talking about Liverpool as an option for the title this year. At this moment, I think we have a squad big enough and good enough to compete in every competition.
"So while the League is a priority because we haven't won it for so long, we also have ideas for the Champions League, the FA Cup and the League Cup. We will be fighting for everything - every single competition.
"I don't know what Ferguson is thinking when he speaks about us.
"The only thing I know is that Gabriel Heinze is not here and we need to manage with the situation we have."