The 84-year-old Old Lady legend believes his ex-team will struggle to compete with the continent's best until they become more physically imposing
Antonio Conte's men have coasted to their second Scudetto in as many years this season, but their fortunes in the Champions League did not prove as fruitful after bowing out 4-0 on aggregate to Bayern Munich in the quarter-final stage of the competition.
Speaking to Corrierre dello Sport, Boniperti belives the Bianconeri boast the personnel required to compete with Europe's finest but stressed the need for physical improvement before launching another assault on the competition next season.
"To win in Europe we need to improve on our physical power. We need to get into this mentality of being physically strong as well as mentally."
The 84-year-old, who won five Serie A titles with the Turin-based club, also hit back at claims Juventus were the strongest in a mediocre field by suggesting the club's detractors were envious of their achievements.
"Winning a championship is always difficult, but to win two in a row is far more difficult," he continued.
"Some say we won a mediocre championship but maybe they're jealous. We should remember how difficult it is winning a title in Italy. It was [difficult] in the 70s, 80s, 90s and it still is."
Conte's men need a further point to match their points total from last season (84) and, with the league title already wrapped up, Juve will now set their sights on breaking the club record for points won in a single season - which currently stands at 91.