"It will be a surprise," said Conte on Friday. "He's a legend for this club and in this season he has been very important to win this title. For this reason I think I have to take my time and to make the best decision for him."
Terry joined Chelsea 22 years ago when he was 14. He rose through the youth squads to make his first team debut when Claudio Ranieri led the side. He was the skipper when Jose Mourinho steered the club to their first top flight title for 50 years in 2005. Terry was also the lionheart in the defence when Mourinho repeated the title winning feat in 2015.
But under Conte, the former England captain has failed to feature regularly in the Premier League and started for the first time since September in the 4-3 win over Watford on 15 May.
Terry will leave Chelsea after more than 700 senior appearances and 15 major trophies including five Premier League crowns. Conte says Terry can play on and Bournemouth, West Ham and Swansea City are reported to be interested in his services.
"John has all the possibilities to continue his career," Conte added. "We all know that he wants to play regularly and for this reason he has decided to leave. I think he has the possibility to do this, because he's still strong. I think in the moment I called him to play he showed this.
"When you arrive at this point of your career it's very important to feel yourself, to feel your body, to feel your mind, to feel if you have still desire, still will to fight to arrive every day and work very hard. If you feel this, it's right to continue to play, to continue your career. John has all these characteristics."
Victory for Chelsea over relegated Sunderland would be a record 30th win in a Premier League season and it would break their own mark from the first two campaigns of Mourinho's first spell as boss in 2004-05 and 2005-06.