The two players arrived on loan in the latter stages of the summer transfer window, with Cancelo moving from Manchester City, while Felix made the switch from Atletico Madrid.
Both have been important members of the first team since moving to the club, with Cancelo scoring twice and registering one assist in 14 appearances, while Felix has three goals and four assists in 14 outings.
Deco has said that "there is no doubt" the club want Cancelo and Felix to remain with them next season, but the club's sporting director added that it is still "early" to talk about what will happen in the summer of 2024.
"There is no doubt that we want to have them next season because they are valid for the squad," Deco said in an interview with RAC1.
"We are still in November, it is early. But of course, we are already thinking about it. We see how the season is going. We are happy with their performance How? We'll see, these are discussions for later.
"Cancelo has already played, as we knew from the possibilities he can give, as a right-back, but he can play as a left-back, as a winger.
"I have not seen anything strange in Cancelo's lineups because it is something he can do, respecting that his base position is that of full-back.
"As for Felix, he is playing in his position, he is a playmaker who goes inside, who makes combinations, but since he arrived he has had to play a lot."
Deco also insisted that Ansu Fati can have a future at Barcelona, with the Spain international currently on loan at Brighton & Hove Albion in the Premier League.
"Ansu can come back, of course. He's very young and he's happy now. He asked to go out on loan looking for minutes and decided on Brighton and I think he did well," he added.
"We're following him because Bojan, who is doing a great job, is watching him. The future depends on him. He can return to Barca, there is no doubt."
Fati's future was the subject of much speculation over the summer, and it was confirmed in the latter stages of the transfer window that he had joined Brighton on loan.
The 21-year-old has featured on 13 occasions for the Seagulls since his arrival, scoring four goals and registering one assist in the process.