Julio Diaz looks back on his career so far and doesn’t like what he sees.

Ten years ago, he was a hot prospect, one of those gifted young fighters over whom everyone loves to gush. Today, after 40 fights and four disappointing losses, he remains a bona fide lightweight contender but no one would call him a star.

“The Kidd” from Coachella, Calif., is a two-time world titleholder but lost the big fights that might’ve lifted him to the status he believes he is destined to attain.

Diaz (36-4, 26 knockouts) is frustrated to say the least but, at only 29, he continues to battle and remains confident that it’s not too late for him to realize his dreams.

“No, my career hasn’t gone like I expected,” said Diaz, preparing to fight Rolando Reyes on the Edwin Valero-Antonio Pitalua undercard Saturday in Austin, Texas. “It hasn’t gone like a lot of people expected. It’s been a little rocky, a roller-coaster. I’ve learned, though. And I’m still here.”

One trait of a great fighter is his ability to get up when he’s knocked down. Diaz does that.

He was 23-0 when he faced veteran Angel Manfredy in a title eliminator in 2001 and lost a split decision. Two fights later he was stopped in one round by journeyman Juan Valenzuela, after which his contract with Top Rank — one of the major players in the sport — was not renewed.

Yet he got up.

Diaz then won six straight fights, the last one over Javier Jauregui to win the IBF lightweight title in 2004. In his next fight, brawler Jose Luis Castillo dominated him en route to a 10th-round knockout that stopped his momentum cold.

Yet he got up.

He then won four more fights, the last one a third-round knockout over Jesus Chavez in 2007 that returned the IBF belt to him. In his next fight, then-unbeaten Juan Diaz stopped him in nine rounds to unify three of the four major titles.

Yet he got up.

Diaz won twice subsequent to that setback to set up a high-profile matchup against Joel Casamayor on the “Lightweight Lightning” card in Austin, but Casamayor – a slick southpaw for whom Diaz geared all his training — pulled out because of an injury and was replaced by Reyes (30-4-2, 19 KOs).

Again, he was disappointed. A big fight, one in which he might’ve taken a big step toward that elusive stardom, became just another fight.

Yet he fights on.

“I’m very proud to say that after every defeat, I’ve never let myself fade away,” he said. “I always come back strong, proving what I got to prove. After the Castillo fight, I came back and beat everybody in front of me. After another defeat, against Juan Diaz, I knocked guys out and I’m here again. Now this, two months of training [for a southpaw] out the window. That was motivating for me, fighting a big name like Casamayor.

“I feel like a strong, solid lightweight. I wanted to take advantage of it. Now I’m fighting a replacement. Not only do I have to win, I have to win with no problems or I look bad. I’m motivated, though; I have to be.”

Diaz blames his management team – Sycuan Ringside Promotions and former manager/trainer Lee Espinoza – for periods of inactivity in his career, which he said contributed to his setbacks. They simply had trouble getting him big fights.

He was idle for 10 months before the Castillo fight – and probably too raw to face an established brawler like Castillo — and he fought only twice in two years before the Juan Diaz fight. He also blames himself for his problems. He ballooned to 170-175 pounds before the Diaz fight.

“I came in with a lot of ring rust and I looked like a bum in there,” said Diaz, referring to the Juan Diaz fight. “My biggest fight was with the scale. Day and night, everything I did was for the scale; whatever I could do to sweat was all the mattered. His name never even came up in training camp.

“Do I blame myself for that? Yes and no. No, because I had no activity for so long. Yes, because at the end of the day I was responsible for keeping myself healthy and within my weight range.”

Diaz remains with Sycuan for at least another year, when his contract expires. However, he’ll step into the ring Saturday for the first time with new manager Jose Castillo.

The fighter seems to be re-energized by the change, as if he’s getting a fresh start. Meanwhile, the manager, who also handles Valero, has similar enthusiasm for the new arrangement and is optimistic about Diaz’s future.

“Unfortunately for Julio, the promoter he signed with doesn’t have the (television) dates other promoters have,” Castillo said of Sycuan. “He’s had to rely on Golden Boy and Top Rank, the two biggest promoters now, to get on cards. He hasn’t been able to get fights.

“Now, he’ll definitely be busy. This fight was supposed to be canceled (when Casamayor pulled out) but we did whatever we had to do to get him a fight. That’s how it’s going to be.”

Diaz, who most likely will move up to 140 pounds after this fight, looks forward to the future.

Castillo, his manager, said he likes the idea of a showdown with Juan Manuel Marquez at 140 pounds. Diaz doesn’t care who is in the opposite corner – as long as a large number of people know that fighter’s name.

“I’ll fight anyone who takes my career further,” he said. “I want people to say, ‘Hey, this guy could beat Julio.’ I don’t want to fight some guy I’m supposed to beat with no problems. Those fights don’t get me anywhere.

“ÔǪ I just have to wait a little longer, be patient. It’ll come. I haven’t come this far to fall flat on my face.”

If he did, he’d get up.

Michael Rosenthal can be reached at [email protected]