Diesel was asked by Collider about Baby Groot in Guardians of the Galaxy Vol. 2 and said that this won’t be the same Groot audiences came to know and love from the first film.
For the sequel, Groot will remain in his Baby Groot form from the end of Guardians and their encounter with Ronan.
Until the trailer arrives, imagining Baby Groot getting himself into trouble or fighting bad guys will have to do for now.
I always think of the Groot that we saw in the first Guardians as a college level Groot.