Terry injured his knee in his comeback game against Liverpool last month, having served a four-match domestic ban for racially abusing Queens Park Rangers defender Anton Ferdinand.
Former manager Roberto Di Matteo, sacked on Nov. 21, said midway through last month that Terry was expected to miss around three weeks following his collision with Luis Suarez when he strained ligaments.
The Premier League club travel to Japan next week to play a Club World Cup semi-final on Thursday.
Chelsea's third-highest scorer Lampard has struggled with a calf injury all season and has not played since Oct. 23 but Benitez said he would be fit for Saturday's game at Sunderland (1500 GMT). (Reporting by Tom Pilcher; Editing by Clare Fallon)