Lampard, who departed Stamford Bridge earlier this summer, leaves with a string of accolades after a glittering 13 years at the club.
The veteran is the highest-scoring midfielder in Premier League history, and leaves Chelsea as their all-time top scorer with 211 goals.
Terry is a close friend of his former teammate, and said that not having his pal with him next term will be something that may take some getting used to.
He told the club's official magazine: "It feels different coming in and Lamps not being sat next to me. We have sat next to each other in the changing room since... well, since he signed for the club really. I’ve become really close to Lamps and Ash (Ashley Cole) and they were my two best mates at the club."
"So I’m really sad to see arguably the best player the club has ever had, in Lamps, move on, for what he brought to the dressing room and as a mate. You understand that you all get older, but you just hope that point doesn’t come."
However, Terry, who scored in Chelsea's 5-0 win over Wycombe Wanderers on Wednesday evening, has tipped recent signing Cesc Fabregas to fill the void left by Lampard.
"He’s a very good signing," Terry added. "He is great on the ball, a great box-to-box player, he scores an awful lot of goals as well and he has got an aggressive streak in him too – I certainly remember that from his Arsenal days. I’m sure he is going to fit in really well at Chelsea and do well in the years to come."
"'I think we should be very competitive,' he said. 'We were close last year, but just unlucky at times. With the signings we have made and a couple of younger players who I think will surprise a few people this year."
"I think this should be a very good year. We want to win trophies – that is always the aim from the outset for me."