Sassuolo coach Eusebio Di Francesco said Domenico Berardi turned down the chance to return to Italian champions Juventus before the start of the season.
Berardi joined Sassuolo permanently from Juve in June following a successful loan spell in 2014-15.
Di Francesco has now revealed the 21-year-old Italian, who has scored two goals in seven Serie A appearances this season, rejected the opportunity to go back to Turin.
"He didn't go to Juventus because he chose not to as he wants to complete his development with us," Di Francesco told La Gazzetta dello Sport.
"He is our Arjen Robben. I have no doubts he will become a great player."
Berardi took Serie A by storm last season, scoring 15 goals in 32 league appearances.