The Blues duo could be left on the bench for the showpiece fixture against Benfica next Wednesday.
Lampard and Terry have been key figures in all of Chelsea's big matches over the past decade, but Benitez may look elsewhere next week after refusing to make any guarantees regarding his starting lineup.
Speaking to reporters, Benitez said: "I will do what I have to do to win it and if I can help Frank at the same time, I will do it.
"At centre-half the competition is really hard. Gary Cahill, Branislav Ivanovic and David Luiz are also doing well.
"So now we have four centre-backs who have to compete with each other and I cannot say anything about Terry playing in the final. I haven't decided yet."
Lampard is one goal short of equalling Bobby Tambling's all-time Chelsea goalscoring record of 202, but he has not been a fixture in the Blues team under Benitez.
The 34-year-old has been part of a midfield rotation, and Benitez may opt to go with Ramires and John Obi Mikel against the Portuguese league leaders.
Uncertainty continues to hang over the future of Lampard, who has just three weeks remaining on his Stamford Bridge contract.
The England international has repeated his desire to stay at Chelsea - the club he joined in 2001 from West Ham - but he's yet to be offered a new contract.
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