The Celtics still aren't sure whether JaJuan Johnson is physical enough to consistently play PF. Johnson said he's most comfortable at PF for the moment, but Boston may end up trying him at SF. Either way, they want to see more from him this year. "We just want him to do other things outside of scoring," said Tyronn Lue, who is coaching the Celtics' Summer League team."Doing the right coverages on defense, blocking shots, running the floor, getting rebounds, stuff like that."