The Rossoneri face PSV Eindhoven next week in the first leg of their Champions League play-off.
"I've been working so hard," he told Milan Channel. "Today was the first day I worked with the rest of the team, so hopefully my shoulder responds well.
"I feel much better and my goal is to be ready for the Champions League."
For the big stories and the banter follow us on Twitter: @tribalfootball