NEWPORT, R.I. -- When you're an NBA rookie, even a three-man fast-break drill is enough to raise your adrenaline to a dangerous level.
Which is exactly what happened to Luke Harangody during the Boston Celtics' second training camp session on Wednesday on the campus of Salve Regina University. Lining up at one of the wings in a unit that featured Shaquille O'Neal in the middle and Stephane Lasme on the other side, Harangody sprinted too quickly out of the box, fumbled an outlet pass and missed a layup as the group stumbled through the drill.
Rivers instructed the unit to run it again and 38-year-old O'Neal -- the same player who had to ask Rivers who Harangody was when his signing was announced on the same day of the Big Shamrock's introduction in August -- shot Harangody a stare typically reserved for an opposing center with sharp elbows.
The group completed the drill with fewer hiccups the second time, with Rivers imploring Harangody to crank up the speed on his way back up the court. Harangody knows Rivers is simply trying to bring the best out of him.
"Doc's been great with me," Harangody said Friday. "I'm a guy that likes to go 100 miles per hour, but I play so much better when I slow down and relax. Today I feel like I finally did that and I probably had one of my better days."
Harangody, a second-round draft choice (52nd overall), isn't playing for a job. No, despite the late selection, he already proved he was NBA ready by starring for the Celtics' summer league team in Orlando in early July, which helped him earn a two-year guaranteed deal.
But even job security doesn't take away any of the pressure when you're a wide-eyed rookie on a team that is likely to boast more future Hall of Famers than first-year players this season.
And despite a penchant for keeping rookies glued to the bench, Rivers said he understands what Harangody is going through, and believes he can contribute this season.
"He just needs to slow down," Rivers said. "It's so much stuff for him now, his head is spinning. He'll get it, but it's going to take some time.
"It's an adjustment for any college player, especially being the star scorer. Now you have to show on pick-and-rolls, you have to get in transition. And you have to play against guys like Kevin Garnett, so the talent level is a little bit better than in college. Plus, we're putting in five [sets] per day and the first couple days he's asking me, 'How do they remember it all?' I said, 'They just do, and you will, too. You gotta train yourself to do that.' We don't have 35 days of practice before the first game [like in college]. That'd be nice, but we don't."
Harangody is coming off a decorated four-year career at Notre Dame, where he was a three-time All-American, averaging 21.8 points and 9.1 rebounds during his senior season. He's the only player in Irish history to score more than 2,000 points and grab 1,000 rebounds, finishing with 2,476 points and 1,222 rebounds for his career.
Now Harangody must acclimate to being an end-of-the-rotation player and that might not even be his toughest adjustment. His biggest challenge will be figuring out how his 6-foot-8, 246-pound frame translates to the NBA level. No longer can he utilize his size to dominate inside like he did in the Big East, not when there are 7-foot-2 behemoths like Shaq roaming the paint.
With that in mind, a reporter asked Harangody if anyone in particular had wowed him in sheer stature, just as O'Neal was wandering behind him on his way out of the gym Friday.
"Go ahead and say Shaq," O'Neal said with a smile.
Harangody playfully fired back, "Shaq's a little overrated," as the big man walked out of earshot.
"But, no, seriously, Shaq blows my mind everyday," Harangody admitted. "You can see it on TV, but when you see it in real life, it's just like, 'Wow.'"
Even still, Harangody said he doesn't feel out of place. He knows he can compete at this level. He showed glimpses of his potential at summer league, where he averaged 16.6 points and 6.8 rebounds over five games. What's more, he displayed NBA 3-point range that could allow him to find a role as a big-frame small forward, a position the Celtics are thin at.
But the 3 is regarded as maybe the most athletic position on the floor, one occupied by the likes of Paul Pierce and LeBron James, which means Harangody has to find a way to defend players that might be naturally quicker than he is.
Fortunately, Harangody's biggest strength might be his grit. It's on display below his left eye, where a scar remains on his cheek from where he needed stitches after a collision while chasing a loose ball in summer league.
It's the one thing you can't quite teach at this level. Everything else will come with time.
"That's why I'm in the weight room every day and watching what I eat,"
said Harangody, who looks sleeker and more toned already.
"it's obvious I have to adapt. ... I have different strengths and weaknesses now."
Harangody said that just playing with this collection of talent has made him a better defender already and he's grateful for the way the veterans are aiding him on the court.
Off the court, he's subject to the typical rookie treatment, which he said has included being sent to local convenience stores in search of snacks. He's simply hoping to avoid a Dez Bryant-like $55,000 dinner tab.
"I might not do that," Harangody said. "I don't know if my checking account is that big."
It might be one day. But the first step for Harangody is calming down and letting his natural talents take over this season. Soon enough he'll be the one staring down a rookie for fumbling the ball in fast-break drills.
Chris Forsberg is the Celtics reporter for ESPNBoston.com. Follow him on Twitter.