Bianconeri director Fabio Paratici was in London this week to watch Hummels during the Champions League game with Arsenal.
"I am honoured that Juventus are interested in me," he told Tuttosport.
"Knowing such an important club wants to sign me is very exciting and forces me to ask myself some questions.
"I can see myself playing abroad, even if at the moment I am concentrated on Borussia. Who wouldn't want to play for Juve?"