I know somewhere in the universe, you’re gonna see Groot and Hulk battle. You can write it somewhere, you’re gonna see that poster: Groot vs. Hulk.”
The two characters have already fought in the comics, and Hulk won. But that doesn’t guarantee anything. He also mentioned how he would love to see a Rocket & Groot movie after Infinity War. None of this has been confirmed, but it seems like Vin Diesel is pretty confident that this will happen.