Terry will leave Chelsea after 22 seasons in the summer but wants to continue playing.
He has struggled under Conte this season with injuries and then the form of others restricting his appearances to just 10, and only four Premier League starts.
He last played in the middle of February against West Brom in a 2-0 victory.
Antonio Conte has spoken about John Terry's Chelsea exit
John Terry is to leave Chelsea this summer after 22 years at the club
“I am not surprised about this [the reaction]," Conte said.
"I am repeating that John, for me in this first season, is very important. He is helping me on and off the pitch.
Chelsea line-up predicted to face Tottenham Hotspur in the FA Cup semi-final Thu, April 20, 2017
Express Sport predicts who will start for Chelsea in their FA Cup semi-final clash against Tottenham Hotspur at Wembley on Saturday (5.15pm)
Play slideshow Getty Images 1 of 12
Who will Antonio Conte pick to start for Chelsea against Tottenham?
“He is a great captain, the problem is that John wants to play regularly and for this reason we have to respect his decision. I was a footballer and when you arrive in this point of your career, and your body tells you to continue it is right to.
“We have to respect his decision.
“If you ask me if next season it is a serious loss…yes, I think so. I am seeing what John is doing this season in the changing room. We are building a foundation and he is important to this.”