The 22-year-old impressed for the club on a two-year loan spell starting in 2019/2020, and was then signed permanently last summer.
Traore, who played 32 games in all competitions last term, is an Ivory Coast international.
According to Sassuolo CEO Giovanni Carnevali to Corriere dello Sport, there are proposals for the attacking midfielder.
He said: "We have received a request (from Leeds), but I repeat, we will not sell all of them."
Meanwhile, Leeds and Barca are involved in negotiations regarding the Whites' Brazilian midfielder Raphinha.