Domenico Berardi may have feared not getting enough game time at Juventus in deciding to stay at Sassuolo, according to coach Eusebio Di Francesco.
Berardi, 21, has enjoyed three fine Serie A seasons, scoring 38 goals to be linked with a move away.
Juventus were said to retain a buy-back clause for the forward, who they previously co-owned.
However, Berardi is set to stay at Sassuolo and Di Francesco believes his desire to be playing regularly may be behind the decision.
"He's a great guy, who is attached to Sassuolo and myself," he told Il Centro.
"For me, he is ready for a big team, perhaps he thinks that is Sassuolo and therefore he stayed.
"Juve? Maybe he had a fear of not playing enough.
"It's hard to accept the change and I am happy I get to coach him again. I'm looking forward to his growth."