He is the little brother of the Big Three; the pesky, amazing, maddening, motivating, infuriating point guard who literally makes the Boston Celtics go.
Rajon Rondo controls the ball -- and quite possibly the fate of the Celtics -- as they prepare to meet the Miami Heat in the second round of the NBA playoffs.
Rondo is only 25 years old, while the trio of veterans that have invited him into their inner circle heretofore known as the "big four" average roughly 34.7 years.
You would think the old vets benefited most from Doc Rivers' decision to shut down his regulars in the final week of the regular season. Yet it was The Kid who wound up reaping the benefits. It gave him time for his body and his mind to heal from a disconcerting finish to a challenging season.
"What is it they say? That which doesn't kill you will make you stronger,'' Rondo said. "True in my case.
"I don't know if it was fatigue, or injuries. Regardless of what it was, every player goes through it at one point in time.
"The guys kept saying it, but I had never struggled like that before in so many different ways. It was difficult, especially after playing at the level I did last year. There were expectations I had to meet.''
Some of those expectations were self-imposed. Rondo's electric abilities in the open court led him to believe he should be mentioned in the same conversation as Derrick Rose, Chris Paul and Deron Williams. Rondo inserted himself into the discussion last spring by declaring himself the best point guard in the league.
His didn't play like it in the latter half of 2010-11. His assists dwindled to fewer than eight a night. From March 13 to the end of the season, Rondo shot 29 percent from the floor; worse, he was a non-factor in a number of games defensively. The Celtics played .500 basketball (9-9) during that swoon.
Rondo recouped some of his swagger in a 4-0 postseason sweep of the New York Knicks. He dominated the series, averaging 19 points, 12 assists and 7.3 rebounds a game and shooting 50 percent from the floor. Yet skeptics of Boston's enigmatic point guard want to see it against a more formidable opponent than New York and Toney Douglas. Knicks coach Mike D'Antoni even wondered aloud how Rondo would fare without the Big Three in, say, Minnesota.
The criticism stung, but certainly didn't deflate Rondo. He doesn't care if it's Toney Douglas, Mario Chalmers or Dwayne Wade guarding him. He plans to take on all comers.
"I won't say that nobody can guard me, but when I'm looking at a guy, I don't really see the player in front of me,'' Rondo said. "I'm looking at the second line of the defense, because that's where I'm headed.
"In transition? Definitely, I don't think anyone can stay in front of me.''
So the old Rondo is back, the cocksure, confident floor leader who averaged 13 plus assists a night in November and December and led people to believe the Celtics were the team to beat. That was before teams sagged off and dared him to shoot, before Rondo quit driving to the lane as his struggles from the free-throw line mounted, before his defensive presence -- once his most impressive attribute -- fizzled into a pattern of inconsistency and disinterest.
"What's Wrong with Rondo?" became a routine headline as the Celtics losses accumulated.
"I don't want to make excuses, but my body wasn't right,'' Rondo said. "It wasn't responding the way it always had. My game is speed, energy, and now you get a tweak in your ankle and that slows you down.
"My hands started hurting. It was almost like arthritis. Any little hit and they would just throb and throb. Then I had the plantar fasciitis, and that wouldn't go away, so you had all these nagging things that added up. I tried to play through it. Some days I did better than others.''
His coach, his general manager and his teammates tried to coax him back on track. They all told him the same thing: When you push the ball, you are better and the team is better. Kendrick Perkins, his best friend who was traded to Oklahoma City in February, urged him to rediscover his passion for the game. Rondo countered the game wasn't fun for the first time in his life.
"The main thing was we were losing,'' Rondo said. "And I felt the reason we were losing was because of me. I put a lot of pressure on myself. I wanted to finish the season well. That was the biggest concern for me, to find a way to get better, because we weren't playing well, or moving the ball, and that was on me.''
As Boston's scoring plummeted, shooter Ray Allen corralled Rondo and tried to discern why the ball had stopped moving. Allen's touches had decreased dramatically, sometimes to just one shot in the final quarter.
"Ray was frustrated,'' Rondo confirmed. "Obviously, if he doesn't get the touches it takes away one of our biggest strengths. When he hits those 3s it is such a huge boost. It opens up things for everyone else.
"So he'd vent a little bit. We all knew what we needed to do. We needed to execute on the offensive end if we wanted to go anywhere in the playoffs.''
Rivers simplified the offensive sets for the postseason in deference to the new players, who, according to the coach, "only knew about half of our stuff.''
Rondo's energy level was back to warp speed against New York. He was an agitator again defensively and active around the glass, sure signs he was feeling better.
"The biggest thing is for me to rebound,'' he said. "When I'm the first pass on the break, we've got a good chance of getting decent looks, even in the fourth quarter.
"Things tend to slow down at the end of games, but I've got to keep pushing it.''
Rondo pointed to one of the rare quality wins in March, against San Antonio, when he submitted 22 points, 14 assists and five boards in a win.
"The last 4-5 minutes of that game I kept pushing the tempo,'' he said. "Danny [Ainge] is always talking to me about that. Teams tend to relax a little at the end of games. They expect you to walk it up, so you can catch them off guard with a push, and a quick 3.
"If you do it right, it can change the outcome of the game.''
Boston has identified thwarting Miami in transition as one of the keys to the series, yet Rondo believes the Heat should be worried about the same thing.
"People don't see us as a running team, but I think we are,'' he said. "We have the two best wings in the game in Paul [Pierce] and Ray. Kevin [Garnett] can shoot with anyone from the elbow and Jermaine [O'Neal] is the classic trailer.
"You hear a lot about our defense, but if you look at the big games we've won, it was because we were pushing it.''
Miami's strength lies in the talents of Wade and James, two physically strong players who aren't about to let a skinny, bony point guard penetrate the paint untouched. While Rondo has averaged 12 assists a game against the Heat this season, the rest of his offensive numbers (7.5 points a game, 37 percent shooting) have been subpar.
"It doesn't matter,'' Rondo insisted. "I'm going to attack those guys. I'm going to make them do their job. I'm driving right at them. If they block my shot, then they do.
"If they're blocking my shot, who is guarding Ray and Paul? It's about adjustments. If they block my shot the first time, then the second time, I'm doing something different.''
Rondo shot 53 percent from the line against New York, but insists his days of worrying about making them are over.
"I'm not thinking about that anymore,'' he said. "If I get to the line and get us into the penalty, then it makes it better for Paul when he makes a baseline cut. When he gets fouled, then he's at the line. Two shots.
"It helps him get into his rhythm, along with Ray. If Ray is fouled with the ball and we're in the penalty, he's going to the line. That's two shots, two points.''
The Heat are favored in the series and hold home-court advantage but Rondo won't give them the edge.
"Obviously, we've only won four games,'' Rondo said. "We've got a long way to go. But I've always believed if you give us time, and rest, this team is as good as anybody.''
His own reputation is on the mend, with an aim at eradicating the words indifferent, moody and inconsistent from his resume.
"When you play at a certain level, people come to expect it every night,'' he said. "I've come to expect it every night.
"That's how you separate yourself.''
The little brother continues to grow on the job. Still, as the Big Three have learned, they're going nowhere without their fourth wheel.
Jackie MacMullan, who has spent nearly 20 years as a beat writer and columnist in Boston, is a columnist for ESPNBoston.com.