Interim manager Benitez claimed the Stamford Bridge decision-makers who have halted contract talks with the England midfielder had no doubt about "his condition, his levels, his quality".
His wage, age, 34, and recent injury record might come into consideration when debating a new deal but Benitez told BBC Sport: "For sure, he's a fantastic player, a great professional - there's no doubt about this. Also, when I talk to the people in charge, they are telling me the same, so nobody has any doubt about his condition, his levels, his quality. So the decision could be analysing different things, not just the quality of the player."
Lampard insisted he had "two or three years at least" left to give as an elite footballer - even if Chelsea appeared to think otherwise.
He admitted on Thursday his glittering career with the European champions could be drawing to a close after revealing he was not in talks with them over a new contract to replace the one that expires next summer.
Lampard appeared resigned to his fate after helping Chelsea into the Club World Cup final in Yokohama, coming off the bench against Monterrey for his second appearance since recovering from a troublesome calf problem.
That compounded an injury-hit 2012 but Lampard made it clear he had more to give.
"I feel like I have two or three years, at least, in me at the top level," he said.
"It is not for me to decide on this one. It's up to the club.
"Whatever happens, I have had a great time at Chelsea. I am determined to play a few more years and see what pans out in the near future."
- Sports & Recreation