Looks like solid muscle to me. He doesn't need to bulk up.
Here is a video of Jaylen Brown working on his game under the watchful eye of Stevens. Enjoy
Jaylen Brown needs to eat some more steaks.... could bulk up a bit more
I believe he is Vegan.
He is kinda thin..... mix in some steak and potatoes Jaylen.
Watching him in the court, he looks plenty strong to me.
1957, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1968, 1969, 1974, 1976, 1981, 1984, 1986, 2008