The Belgium international has broken his silence on the ongoing speculation surrounding Di Francesco, who only took over as head coach in June when Luciano Spalletti departed for Inter Milan.
The 48-year-old has managed to guide Roma to just one win in his opening three games, while they were held to a 0-0 Champions League Group C draw against Atletico Madrid at the Stadio Olimpico on Tuesday.
It has resulted in claims that Di Franceso is already under pressure and he has not managed to win over the support of the players or president - something Nainggolan has vehemently denied.
"Di Francesco? There’s been too much talk about him…", the 29-year-old told Il Romanista.
"[The media] have also dragged [President James] Pallotta into it, but he didn’t say anything bad about the coach. Whoever says we don’t believe in him is talking rubbish."
Nainggolan added: "We’re talking about nothing. Do you want to know what I like best about this coach? His great personality.
"He knew it'd be difficult to replace Spalletti, but he's had no problems. He’s explained his ideas to us and he’s carrying them out with great determination."