Oscar Pistorius, of South Africa, shoots out of the blocks for the 400-meter race during the Prefontaine Classic track and field meet in Eugene, Ore., Saturday, June, 4, 2011. (Don Ryan/AP)

Jeremy Wariner was the best 400-meter runner in the world before 2008, a virtually unbeatable champion from the United States. Oscar Pistorius was an inspirational speedster known as the Blade Runner, a South African with two prosthetic legs and Olympic hopes.

The summer of 2008, however, offered crushing disappointment for both.

Wariner missed the Olympic gold in Beijing, ending a four-year victory streak in major championships and setting off a slide that continued to the 2009 world championships in Berlin. Pistorius got clearance to compete in the Games after a court ruled he gained no unfair advantage from his prosthetic legs, but he failed to achieve the qualifying time and had to settle for utter domination at the summer’s Paralympics.

The celebrated pair will face each other in the 400 meters at the Adidas Grand Prix in New York on Saturday, yet each will be far more concerned with advancing his personal and redemptive climb to this summer’s world championships in Daegu, South Korea, and the 2012 Summer Games in London, than the dynamics of the star-studded matchup.

“Everyone gets up for a big race with big people running the race,” said Wariner, 27, the 2004 Olympic champion. “Everyone wants to go out there and win, beat people, but at the same time you just can’t go out there and focus on that . . . I’m more worried about the end of the season than the middle of the season.”

Wariner, who finished second in a sluggish 45.43 at last weekend’s Prefontaine meet in Eugene, Ore., said his season’s primary focus is on reclaiming the gold medals he lost to LaShawn Merritt. Merritt, after defeating Wariner at the 2008 Summer Games, edged him again a year later at the world championships.

Merritt tested positive that winter for a banned substance contained in a male enhancement product he took several times. Though an arbitration panel ruled he did not intend to cheat, it is unclear whether Merritt will be able to defend his titles at the world championships or Olympics. Both questions are under review.

“That’s the obvious goal,” Wariner said. “Everyone wants to go to the world championships and win the world championships. . . . It was difficult after going out and dominating for so many years . . . to go out and get second, especially losing the world title and the Olympic title.”

Pistorius, whose legs were amputated below the knee before his first birthday because he was born without fibulas, isn’t chasing any particular nemesis. He’s chasing a time. He finished last in last weekend’s race in Eugene in 46.33 and isn’t projected to fare much better Saturday, but he doesn’t care how many super-elite able-bodied athletes beat him. Pistorius simply wants to get faster.

For an invitation to Daegu and guaranteed place in the 400 event, he needs to run a time of 45.25 or better. Pistorius, who plans to run five more races internationally this summer, said it would be a great relief to not take his qualification down to the wire.

Both Wariner and Pistorius look back at 2008 with a mix of cringing and determination. Wariner said a torn meniscus and cyst in the back of his knee at least partly contributed to his feeble finish of the Olympic final, where he faded behind the blazing Merritt.

The cyst, he said, had been pressing on the back of his hamstring, hampering his ability to accelerate late in races.

“I’m not going to blame my losses on that,” he said. “But it had something to do with that. Everything came down the homestretch. I had no lift at all.”

The knee had bothered him for about two years before he finally had surgery at the end of the 2009 season, after losing to Merritt again in Berlin. When Wariner returned to competition last year, he won five major international races and finished the year ranked No. 1 in the world. But he has been unable to repeat or improve upon his personal best of 43.45 – the third-fastest time ever in the event — that he ran at the world championships in 2007.

Pistorius won gold in the 100, 200 and 400 at the 2008 Paralympics, but he failed to achieve his Olympic dreams by less than a second — he needed to run 45.55 and managed 46.25 — after clearing a host of legal barriers.

He now admits the disappointing setback might have been for the best. He said he is lighter and more fit than in 2008, and going faster at this point of the season. He says he is ready to advance to Daegu and London — and make an impact beyond that of a curiosity.

“I’m way stronger than I was in ’08,” he said. “I’m about [five or six pounds] lighter than ’08, and I’m definitely a more mature athlete. I’ve gained a little more experience. I think I’m in a better position now than ever . . . not only in times, but also in confidence.”

Given all that, he said, he won’t so easily be able to swallow falling short.

“It’s extremely, extremely important,” Pistorius said. “It’s obviously a dream I’ve had for six years. I’ve been improving gradually every year, been improving my times and getting closer and closer to those qualifying times. It’s a massive, massive goal.”