BARCELONA ’92 OLYMPICS / DAY 11 : Minor Ailments for Powell, Johnson : Track and field: Long jumper has back problem, decathlete has sore foot.

Injuries disrupted training for two U.S. gold-medal favorites, long jumper Mike Powell and decathlete Dave Johnson, as they prepared to begin competition today in the Olympic Games.

Of the two, Johnson appears to be less concerned. Powell also is optimistic that he will feel no more than minor discomfort while attempting to prevent Carl Lewis from winning his third consecutive gold medal in the Olympic long jump.

News of Powell’s injury surfaced Tuesday, when he failed to attend a news conference. His agent, Brad Hunt, said that a recurring back injury suffered in a pickup basketball game last spring, which also has caused tightness in Powell’s hamstring, flared during a workout Monday night.

But Hunt said the injury was not so serious that Powell, of Alta Loma, would be forced to skip today’s qualifying for Thursday’s long jump final.

“He is here to compete and fully intends to,” Hunt said. “If the preliminaries were tonight, he would be jumping. By tomorrow, it will be better.”

Mike Conley, gold medalist in the triple jump, said Powell told him he was 70% to 80% fit.

Johnson, of Pomona, said this week that he is almost fully recovered from a foot injury suffered two weeks before the U.S. Olympic trials at New Orleans in June. Despite experiencing some pain, he set a meet record there.

“We were cautious in training leading up to that meet, and we’ve been cautious at times leading up to this one,” said his coach, Terry Franson of Azusa Pacific.

“But he’s in better condition than he was at the trials. We don’t expect a problem.”

The U.S. Olympic Committee’s chief medical officer here, Dr. James Montgomery, said he reviewed Johnson’s medical file, including a magnetic resonance imaging exam, and found a bruise on a bone in the right foot.

“There’s usually pain with something like that for three or four weeks, and then it goes away,” Montgomery said. “That’s where he is now. He’s not experiencing pain.”

Also Tuesday, the U.S. men’s coach, Mel Rosen, said Danny Everett of Santa Monica will not run in the 1,600-meter relay later this week because of an Achilles’ tendon injury that prevented him from advancing Monday into the final of today’s 400 meters.

That race will pit defending champion Steve Lewis of Fremont, Calif., against Quincy Watts of Inglewood, whose time of 43.71 seconds in the semifinals was the second-fastest ever.