The Argentina attacker is being linked with a January move to Galatasaray.
But Capello told La Gazzetta dello Sport: "I always keep the good players.
"If we discuss Dybala we can discuss anyone. He has some physical problems, we know that, but when he's well and goes on the pitch he almost always makes the difference."
On veteran Roma coach Claudio Ranieri, Capello said: "Ranieri will have time until the end to work and give dignity to the team, which he is already doing very well, with great desire. Claudio seems very determined to me."
Related：
Roma
Dybala