Washington Redskins cornerback Darrell Green's availability for Sunday's NFC championship game against the Minnesota Vikings probably will depend on his threshold for pain.

Medical experts familiar with Green's type of rib injury said yesterday there is little chance he could cause permanent damage by playing Sunday. "You won't puncture a lung or do something bad," said Dr. Jack Andrish, an orthopedic surgeon and sports medicine physician at the Cleveland Clinic.

But this type of rib injury "is very painful," said Dr. John Lombardo, medical director of sports medicine at the Cleveland Clinic and a medical consultant to the Cleveland Browns. He said it feels much like a broken rib.

Green was injured returning a punt 52 yards for a touchdown early in the third quarter of last Sunday's game against the Chicago Bears. As he jumped over the Bears' Cap Boso at the Chicago 35, Green apparently damaged the cartilage connecting the end of one of his ribs to his breast bone. As he broke into the open, he clutched his injured side with his left hand all the way to the end zone.

Yesterday, the Redskins seemed hopeful Green would be able to play Sunday, but they probably will not make a final decision until today, at the earliest.

In medical terms, Green's injury is known as a costochondral tear or sprain. ("Costo" comes from the Latin "costa", meaning rib. Chondral means "pertaining to the cartilage.")

Costochondral sprains are common injuries in sports, particularly in football, wrestling and hockey, according to Dr. John Bergfeld, director of the Section on Sports Medicine at the Cleveland Clinic and team physician for the Browns.

The standard treatment for this type of rib injury is for the application of 20-minute ice packs every hour for at least the first 24 hours after the injury. Sports medicine doctors often tape the area and also prescribe a regimen of rest and, after the first 24 hours, heat. Pain killers and anti-inflammatory drugs (to keep down the swelling) also are used.

"Some people would give a short course of cortisone orally," said Andrish. "Cortisone has gotten a bad name from people who give it for weeks on end, but it can help in this case for a few days."

Another treatment doctors might use on Green is called TENS -- for transuctaneous electrical nerve stimulation. By placing tiny electrodes on the injured area and hooking them to a battery about the size of a pack of cigarettes, doctors can confuse the brain's pain center.

"The brain gets these messages that overshadow the pain signals," said Dr. Carl Highboten, an orthopedic surgeon at the Humana Hospital-Medical City Dallas.

It could not be determined yesterday if the Redskins plan to use the TENS unit Sunday. Team physician Charles Jackson could not be reached for comment.

How Green's rib injury will affect his ability to play also will come down to his ability to concentrate in the face of pain.

"When he reaches for something, or suddenly takes a deep breath, when he's twisting, running down the line or lunges for something, he will probably feel the sharp pain," said Dr. Anthony C. Mustalish, co-author of a chapter on costochondral injuries in the book, "Principles of Sports Medicine".

But if he is taped and well padded, and has some sort of pain relief, doctors say it is possible to overcome the injury and perform well.

"It's the kind of pain that you can grin and bear it," said Mustalish. "With a knee injury, you may not be able to walk. Or a quarterback who has a shoulder tear can't lift his arm off the horizon. But I would guess that generally with a costochondral, you can tape it and learn to play with it."