Speaking to Sky Sports, the Arsenal forward said, "We always joke, he won the Champions League against me [laughs] and I want to win with him and Jorgi [Jorginho] as well. He’s an amazing player."
He added to BBC, "It’s not only about the result, the way we played, the way we controlled then. They have a good team. It was amazing. Kai is an amazing player, so strong and tall, his quality, he helps us a lot. We’re very happy we have him.
"Everyone knows about City’s quality. We have to focus on our game. It's not only City in the Premier League. Liverpool are playing so well and Villa are playing amazingly. We have to focus on us."