Adani was reacting to Juve's dismal home defeat to Como.
"Given what we've seen, Juve make these glaring errors in every game, they've conceded so many goals in so few games," he said on Domenico Sportivo.
"They're Juve players, sometimes you wonder if they're even Serie A players if they make mistakes like that.
"Last year, the finger was pointed at Thiago Motta , who at this point had three more points and was sacked. Then they started poorly with (Igor) Tudor and then he brought in Spalletti, who wasn't written off, so we need to focus on the management team. They're lacking a vision, which should be central to a club like Juve.
"Juve is a team that tests every week; they don't seem to have a clear vision for the team. The coach needs to be consistent even if they finish seventh, or even fifth. We need to lay the foundations and ensure continuity."