The experienced pair's contracts expire at the end of the season, with left-back Cole linked with a move to Paris Saint-Germain and Lampard rumoured to be interesting Chinese teams.
Chinese Super League outfit Guizhou Renhe confirmed recently that they had made contact with the 34-year-old, but were not close to sealing a deal.
When asked if the pair would leave the club soon, Benitez told reporters: "I think so.
"I don't have all the information and it's not fair to tell me I'm only here for seven months and then expect me to have an influence at the club over the next two or three years, but I think that's the case at the moment."
|7/1||Chelsea are 7/1 with Bet365 to win both halves against Manchester City on Sunday
Benitez claimed he was comfortable working under notoriously trigger-happy Chelsea owner Roman Abramovich, praising the Russian's desire to win and admitting it would be easier working under the oligarch than George Gillett and Tom Hicks at Liverpool.
"The priority of the owner was whether I'm a good manager, a good coach, if the players understand me and if we'll be a winning team," he said.
"He was very clear with that and happy with the things I've said. My impression of him was he's a nice person. You can talk with him and he understands and he likes to see you have clear ideas.
"I've had quite a lot of different owners, presidents and chairmen in my 26 years in football and they all liked to talk about football and find out what was going on.
"If you have confidence in yourself and can explain yourself, everyone can understand. But after the owners [Tom Hicks and George Gillett] we had at Anfield – they didn't love each other – this will be easier. I know who the person is in charge."
Fernando Torres is likely to start against Manchester City on Sunday, with speculation suggesting Benitez has been hired in order to get the best out of the former Liverpool striker.
"I don't need to talk too much to Fernando because he knows me and what I'm looking for," he said. "My idea isn't just to improve Fernando but the whole team.
"I can't just focus on him. But when I look at him I see a player with commitment and a desire to improve, just as I do when I look at the others."