Mascherano's current contract - which still has almost three years to run - is worth about £30,000 a week.
That puts him towards the lower end of Anfield's pay structure and has become a source of contention for the Argentine after Benitez warned Barcelona that it would cost them a minimum of £50m to land their man.
Mascherano wants a pay deal to reflect his value in the transfer market - and Benitez has told Liverpool's owners that they must now bring him much closer to £120,000-a-week top earners like Steven Gerrard and Fernando Torres, says the Sunday Mirror.
Benitez said: "I think now is the time to speak to Javier about a new contract. He still has a lot of time on the contract he signed, but I told him that once he came home from the national team then we would talk again.
"Mascherano became unsettled and I had to sit him down to explain that we didn't want to sell him.
"I can understand why he wanted to listen to Barcelona because they are a top side, a club who won three titles last year. It was not an easy time for him.
"But he knew from the first day that we would not sell him. He is an important player for us.
"I showed him from the beginning how important, signing him from West Ham on loan and then buying him even after he went to the Olympics."