The midfielder made the move from Juventus this summer.
“This is something I had been dreaming of and I was watching the draw for the group stages unfold, so I couldn't believe it," said the Bosnia-Herzegovina international.
“I'm very happy to meet up with a club that is in my heart. I was inundated with messages from my teammates, even one from President Andrea Agnelli. He wrote: 'Welcome home!'
“It's a real pleasure to meet up with friends and people I worked with so beautifully over the years. I also said to myself it's better to play this game now than in a Final, no?
“I will always be grateful to Juventus. In fact, I had the opportunity to move to Barcelona earlier, but I didn't think it was the right moment. It might've been damaging to my career, but I always gave my all for Juve and have no regrets.