The 33-year-old damaged a cruciate ligament after just 26 minutes of the Nerazzurri's 2-0 UEFA Europa League victory over CFR Cluj on Thursday, prompting fears that the forward may have possibly played his last game for the club.
Stramaccioni has reassured him that regardless of his setback and advancing years, he remains an indispensable team member, though.
"I've spent a lot of time talking to Diego, I phoned him late at night after the game and we had a long chat," Stramaccioni said at a press conference. "Not only are we all with him, but we're all waiting for him to return. I can't envisage Inter without him next season.
"He's a fundamental part of Inter's future, my future Inter and everyone's future Inter."
Switching his attentions to Sunday's match against Fiorentina, Stramaccioni acknowledged the difficulty of the clash, but remains hopeful that his side could pull clear of the Viola in the Serie A table. Follow GOAL.COM on Twitter
"I can say this with complete confidence - the Artemio Franchi is one of the toughest grounds to go to this season," Stramaccioni said. "None of the big teams have managed to win there and they've all struggled. It's a real six-pointer tomorrow, there are only four points between us and Fiorentina. It's going to be extremely tough."
Follow GOAL.COM on Twitter