LAS VEGAS -- Jaylen Brown played just one game in the Orlando Summer League before being shut down with a bone bruise in his right knee. His start to the Las Vegas Summer League was enough to immediately wonder if that knee was still injured.

Brown said after the game that he "tweaked" that same knee, but that he expects to play in the Celtics' next game Sunday. Hopefully that will yield a better result for the youngster.

Brown scored nine points on 3-of-13 shooting with just one rebound and no assists Saturday in the Celtics' loss to the Bulls. He knocked down two threes off catch-and-shoot situations but he also really struggled around the rim.

More importantly, Brown seemed to drift. He was either a featured part of the set, in which case he struggled with what to do or was notably invisible. How Brown will fit into an offense with so many clearly defined roles for the Celtics next year will be both something to watch, and a crucial part of his training camp.

It wasn't all negative, however. Brown showed off the athleticism that made him worthy of being selected No. 3 last month, as he showed good burst and was able to effectively body power forward Bobby Portis. He also showed some defensive ability, though Portis sliced past him, catching him off guard for a dunk. Brown looked like a player who could wind up as a very strong defender if he settles into his fundamentals and a consistent system.

That theme, however, was steady throughout the game. Brown looked like he could be a rebounder, but had one rebound. He looked like he could be a slashing attacker, but couldn't finish. He looked very much like the jack-of-all-trades that landed him in the lottery, and the master-of-none that had him much lower than his No. 3 spot on draft night.

Jaylen Brown gets drafted by Boston
Jaylen Brown had a tough start in Vegas USATSI

The good news of course is that it was one game, with a bad knee, in his first game at Summer League. Brown was drafted for what he can do, not what he is able to do immediately off the bat. And the toolkit is open for him to do nearly anything. But it was a concerning start for Vegas play most notably because the player taken after him, Kris Dunn, who the Celtics had reportedly been considering, looked so dominant in his opening game Friday scoring 27 points. Maybe that trend reverses itself and Brown winds up having the stronger summer league, let alone actual NBA season or career.

But Brown has a ways to go to know exactly where he's going to fit into the Celtics' overall diagram for the future.

MEANWHILE, WITH YABU

Guerschon Yabusele, however, who was considered an out-of-nowhere pick by the Celtics at No. 16, looked phenomenal. A huge body with surprising athleticism, Yabusele hit 3's, and drove the lane with surprising control. He was like Glen Davis without the Big Baby. Listed at 240 lbs., "Yabu" finished with 10 points and seven rebounds. GM Danny Ainge might have found something with that one.