Rajon Rondo, top, going to the hoop against the Magic’s Rashard Lewis earlier this month, has been the Celtics’ catalyst.

>

AP / Charles Krupa

BOSTON — There is no question that Rajon Rondo is having a breakout season.

He sets the tempo for the Celtics at both ends of the floor, and even though he’s averaging only 10.9 points per game, along with a career-high 7.4 assists and 5 rebounds, Rondo, the point guard for the best team in the NBA, is having an All-Star-caliber season.

“He’s the main catalyst for this team,” Boston guard Ray Allen said.

“He’s so active. He’s getting everybody easy shots,” Boston forward Kevin Garnett said. “He’s making the game look simple and making it simple for everybody out there.”

What’s even more amazing is that it wasn’t too long ago that the 6-foot-1, 171-pound, 22-year-old point guard didn’t even think he was good enough to play in college, let alone the NBA.

His journey started in Louisville, Ky., where he was born. He started playing basketball at about age 5, and he fell in love with the game instantly.

“I kept a ball in my hand growing up,” Rondo said. “I used to always carry the rock in my hand everywhere I went in the neighborhood.”

“I played in the streets a lot. I played a lot of pick-up ball with some friends, and I played with a lot of older people when I was young, so I think that’s why I can take some of the hits I can take now.”

Rondo excelled in football as well as basketball. He played quarterback until his sophomore season at Eastern High School in Louisville. He gave up the sport to concentrate on basketball.

Rondo said that being a point guard and the quarterback require the same skills.

“It’s the same exact position, really; you are the leader on the court and field, and when things go bad, you take a lot of the pressure,” Rondo said. Rondo played basketball at Eastern High for three years. As a junior, he averaged 27.9 points, 10 rebounds and 7.5 assists. That season, Rondo began to believe he had a future in the game.

“I just played basketball just to play,” Rondo said. “I just loved the game. I never thought that I was going to be in the NBA until my junior year.” So Rondo transferred to Oak Hill Academy for his senior season to play against better competition and get more exposure.

Rondo became a McDonald’s All-American at Oak Hill, averaging 21 points, 12 assists and 3 rebounds. He caught the eye of Kentucky coach Tubby Smith, who offered him a scholarship, which Rondo accepted.

He continued to excel at Kentucky. After setting the Wildcats’ single-season record for steals (87) as a freshman, he was named to the Southeastern Conference All-Freshman Team.

As a sophomore, he averaged 11.2 points, 6.1 rebounds, 4.9 assists and 2.1 steals per game. He was named to the 2005 USA Men’s Under-21 World Championship Team, which traveled to Argentina for the FIBA World Championships. He averaged 11 points and 4.5 assists in the eight-game tournament. That’s where he caught the attention of a lot of NBA scouts.

Rondo entered the NBA Draft after his sophomore season at Kentucky and was drafted 21st overall by the Phoenix Suns. Phoenix then traded him to Boston.

After the Celtics struggled to win in his rookie season, they traded for Kevin Garnett and Ray Allen in the offseason. Rondo, in only his second year, was not intimidated by all of the All-Stars on his team.

“I had to get those guys’ respect,” Rondo said. “They respected me. I was the point guard of this team and they were bringing guys in, but for the most part they don’t have ego problems, and when I did tell them something, they listened. They tell me, as well.”

With a second-year point guard with no playoff experience running the offense, many NBA insiders didn’t think the Celtics could win an NBA crown last season, but Rondo did his part to lead Boston to the title.

This year, Rondo is developing into an All-Star. He outplayed Utah Olympian Deron Williams Monday night, scoring a career-high 25 points, with nine rebounds and eight assists. Two weeks ago, against Indiana, Rondo recorded his first triple-double (16 points, 13 rebounds, 17 assists).

“I think Rondo is doing a great job of pushing the ball and finding the open guy,” Boston captain Paul Pierce said.

roblee@projo.com