Juventus fans on Wednesday, August 9, stormed the pitch during a training match against Juventus Next Gen and chanted 'we don't want Lukaku' in protest against the club signing the Belgian striker.
The Italian fans do not want the club to do a part-exchange deal that will see striker Dusan Vlahovic move to Chelsea while Lukaku move the other way.
Juventus' fans consistently applauded Vlahovic during the game, which the senior team won 8-0.
It comes after the Curva Sud ultra group unfurled a banner telling Lukaku to stay away, which read: 'Lukaku stay in Milan, we already have a second goalkeeper'.
The mocking message refers to the Champions League final, when Lukaku accidentally blocked Roberto Dimarco's goalbound effort in their 1-0 defeat to Inter Milan.
Fans began the anti-Lukaku chants within the first minute of the game, according to La Gazzetta dello Sport.
Chelsea rejected a £26million bid from Inter for the wantaway 30-year-old earlier this summer and Todd Boehly wants in the region of £40m.
He was on loan at the Milanese giants last year but the Blues are adamant he will not go out on loan again, even if they don't want him themselves.
Lukaku is understood to be open to Juventus, forcing Inter to pull out of trying to sign him after hearing that talks were being held between Chelsea and the Old Lady.
He was reportedly unhappy that the Nerazzuri left him out of the starting line-up for the Champions League final and so snubbed them this summer after scoring 14 goals in 37 games for them.
Chelsea were willing to table a £38.5m bid plus Lukaku for Juventus' Vlahovic.