Saying,
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.
It’s kind of obvious Hulk would win against Groot but it still makes for an interesting fight.