Carlo Regalia, the former Bari sports director who discovered Cassano, told Tuttosport: "He has found the right environment and he is quickly getting to his best.
"I'm happy that Cassano is back and is showing what he can do. Now I can see that the lad is calmer, like the old days.
"Congratulations to Samp sporting director Beppe Marotta for having thought of the long term and making a tough gamble."
There could be a bidding war for the 25-year-old in the summer with Inter believed to be in pole position, but Regalia believes he would thrive in the Juve shirt.
"I think that Cassano would do well at Juventus. He could be Alessandro Del Piero's heir as they have very similar characteristics. Anyone who does sign Antonio will have done very well."