Chris Spielman's inspiring comeback story ended even before the regular season had started.

They and several other NFL players are attempting to return to the sport they had to leave because of ailments ranging from concussions to depression to cancer.

Giants running back LeShon Johnson is trying to return after treatment for a tumor in his chest. Dolphins receiver Yatil Green wrecked his right knee in each of the last two training camps. Ki-Jana Carter, the No. 1 overall pick in the 1995 draft, has had knee, shoulder and wrist injuries to overcome.

Spielman's comeback attempt was the most publicized -- and the saddest. After neck fusion surgery in 1997, he sat out last season to help his wife, Stefanie, battle breast cancer. Granted his release by Buffalo, the native of Massillon, Ohio, and a star at Ohio State signed with expansion Cleveland. He seemed almost embarrassed by the publicity surrounding his layoff and his return.

During the preseason, Spielman didn't lack any of the fire that was his trademark at linebacker. His leadership and charisma would have been useful for the Browns.

But last weekend, in a preseason game with Chicago, a blindside hit from Bears center Casey Wiegmann made his body tingle from head to toe. He knew it was time to stop for good.

"As a football player, you're trained to feel invincible," Spielman said. "I would love to keep playing, but I couldn't jeopardize my arms and legs.

"Until you have pure medical evidence in front of you, as a player your mentality is, 'I'll beat this,' " he said. "But as they say in football, the films don't lie, and here the images of the MRI don't lie."

Miller knows the feeling. He's trying to catch on as the third-string quarterback with Denver after missing three seasons due to post-concussion syndrome.

After signing with Denver in April, Miller said he talked to a half-dozen experts and neurosurgeons about his concussions.

"I've had every test you could have, and I got clearance from every doctor I talked to," said Miller, who played seven seasons with the Falcons and two for the Rams. "Physically, I still feel like I have a lot of skills left to offer.

"I was going a little bit stir crazy. I needed an outlet for my competitiveness. I didn't like the way my career had ended."

There's no guarantee it will continue, though. Persistent elbow tendinitis limited his work during preseason.

Williams returns from a two-year hiatus with an eye injury, but a bruised bone in his left knee makes his status uncertain for the opener with the Giants. But he appears prepared to resume starting at center.

That's comforting for a team whose offensive line is in flux.

The injury, resulting in double vision, came from being poked in the eye by teammate Bernard Holsey in the opening days of training camp two years ago.

Williams still has trouble seeing when he glances down. The only outward sign of the injury is a tinted visor on the front of Williams' facemask that protects his eyes from fingers and glare.

"Last year, there was just nothing in my future that I saw that was very bright," Williams said. "Being a football player was not even in my mind.

"I'm here, and I'm glad, and I guess I forget about everything that happened in the past. I just want to move on."

So do Spellman, Lawrence Phillips and Rashaan Salaam, whose problems generally were not football related.

Spellman played well in his six seasons with the Chicago Bears, but he was released last year after erratic behavior caused by bipolar disorder, a mental illness treatable by medication, but which can lead to manic behavior if he doesn't take it.

At one point, he was found walking outside in freezing weather without a shirt or shoes. Detroit police used pepper spray to subdue him from attacking hotel security guards trying to break up a fight between two women who were with him.

He also was evicted from his home, pulled over for erratic driving -- leading to his arrest on charges of having a handgun with a bullet in the gun case -- and found napping in his car in the fast lane of a highway. Police officers said he didn't seem to know where he was.

He sat out last season while receiving treatment for the disease and then signed a one-year deal with Dallas for the veteran's minimum of $400,000.

"I'm not even looking back, to tell you the truth, I'm looking forward," Spellman said. "That's the No. 1 thing. If you look back, there's no way you can walk ahead."

Phillips and Salaam would like to outrun their troubles. Both were college stars and first-round draft picks. Neither has established himself in the pros, mainly due to off-field difficulties.

Phillips flopped with the Rams and Dolphins, but not for lack of talent. He was late for meetings, fell asleep in others, didn't learn game plans and had runs-ins with the law. He was out of the league in '98, but had a strong season in NFL Europe, which sparked the interest of the runner-poor 49ers.

Salaam didn't play last year, and he cited an addiction to marijuana for his failure with the Bears.

"It was hard," he said. "It was embarrassing. My pride was shot. It was just a nightmare to be 23 years old and out of football. I couldn't believe what was going on.

"Everybody thinks getting high is cool, you can let it go when you want to let it go," he added. "But it's just as potent as alcohol. It's just as potent as cocaine."

Salaam, like Phillips, is trying to come back in the Bay Area. He's among a group of running backs on the Raiders and has the support of one significant person: coach Jon Gruden.

"I like him as a person and he has something to prove," Gruden said. "He is extremely hungry."