The 18 year-old left Barca for PSG this week after his agents warned Deco that Dro would leave for his €6m buyout clause.
In the end, PSG paid €8.5m to sign the midfielder to ease tension with Barca.
But Deco told TNT Brasil: "If Dro continues to rush things throughout his career, it will be very detrimental to him in the future.
"Sometimes the behaviour of those around him isn't good. PSG didn't influence this decision; it was the player himself."
He continued: "There's a bit of disappointment because (coach Hansi) Flick had given him his first-team debut after bringing him along for preseason. He always helped him.
"His departure is not a tragedy, he is just another player who was part of the first team dynamic."
