The early scuttlebutt from those summer pickup games in Chicago bordered on the hysterical. One breathless account crossed the line entirely:

	Michael Jordan might need to tug on his shorts to catch his breath against young stars like Kobe Bryant.

Michael Jordan ... couldn't even dunk.

Of course, reports of Jordan's professional demise were greatly exaggerated. The fact is, he probably will be dunking on his grandchildren at the age of 60.

Still, at the advanced age of 38 -- Jordan turns 39 in February -- those who wonder about the level of his performance in the coming months are on sound medical ground. Common sense tells us that the 38-year-old Jordan couldn't play with the 25-year-old Jordan, and the medical experts back this up.

A recent Scandinavian report that studied healthy young people who died in auto accidents focused on the loss of muscle fiber over time. Researchers concluded that humans lose about 10 percent of their muscle mass between the ages of 25 and 50.

"Jordan is about halfway in between," said Frank Booth, an authority on muscles and aging at the University of Missouri. "That means, assuming he's normal, he's lost between 2½ to 5 percent. Since there's a rough correlation between muscle mass and power, you could expect a similar drop in performance."

Since it is Jordan we're talking about, "normal" is hardly a word that seems appropriate and performance is a relative proposition. If Jordan could once jump to the moon, now he can manage, say, only 97 percent of the trip. Where he once took off from the foul line and jammed, now you'll have to spot him about five inches. If he averaged 31.5 points over 13 seasons, his age-adjusted output still would work out to a tidy 30-plus points per game.

When he left the NBA stage after the 1997-98 season, Jordan had posted the highest scoring average for the regular-season, playoffs and All-Star game. He won the scoring title in the last 10 full seasons in which he played. No one expects those kinds of numbers this season from Jordan, who will be supported by the lowly Washington Wizards.

Jordan already has suggested that individual statistics will be secondary to his role as mentor for the young Wizard players. "The opportunity to teach our young players and help them elevate their game to a higher level ... strongly influenced my decision," Jordan said in a statement Tuesday.

	“	Personally, I am a skeptic. I wish him well, I don't think it will work and I hope he gets through in one piece. ”
		— Kareem Abdul-Jabbar

This may also be an advance rationalization for reduced performance. Jordan understands his increasing frailty better than anyone; during his feverish workouts in recent months he broke two ribs and suffered from back spasms and tendinitis in his knee.

Historically, 38 is not a terrific age to be playing in the NBA, where teenagers are turning up with increasing regularity. Of the 33 players who have begun a season in the NBA at the age of 38, only two improved on their career average for points, rebounds or assists -- and both come with an asterisk. John Stockton of the Utah Jazz averaged 2.8 rebounds last year (vs. 2.6), but he is a Hall of Fame point guard whose specialty is assists. Dennis Rodman averaged 14.3 rebounds last year with Dallas, but he played in only 12 games -- hardly a representative sample, as researchers are won't to say.

While Jordan's career average is 31.5 points per game, he hasn't hit that number since 1990-91 and even casual basketball fans know that Air Jordan largely had suspended service. The swooping, floating, hang-time jams were mostly the stuff of highlight archives; he had come to rely more on his outside shot and often posted-up smaller guards with his back to the basket. There is talk that he will play small forward in his third tour of duty in the NBA, another suggestion that he isn't as flexible as he once was.

"He's taken three years off and his body is probably doing a lot of strange things," Dallas Mavericks assistant coach Donn Nelson said. "I don't expect him to have the explosion or quickness he used to, but he'll figure a way to win. At this point, his intelligence will be his biggest weapon."

Dr. Peter Jokl, professor of orthopedics at Yale University School of Medicine, concurs. "Explosive performance declines in the mid- to late-20s," Jokl said. "The Type 2 muscle fibers involved in explosion go first, later it's the Type 1 fibers (which supply athletes with their endurance). You can argue that Michael Jordan was at his pure athletic peak at North Carolina, but with experience and age over the years he will compensate."

There are, of course, exceptions to every rule.

George Foreman won the world heavyweight title from Joe Frazier in 1973 at the age of 24. Eighteen years later, he fought Evander Holyfield for the title, losing a 12-round decision.

	George Foreman never let age be a barrier during his boxing career. 'I peaked at 45!' he said.

"I peaked at 45!" Foreman said Wednesday, responding to an e-mail. "One day in the gym, my footwork, balance and thought plan just came together. I put together everything I'd learned over the years into one package. For years, I had tried these things; but at 45, I did them.

"I've heard that doctor stuff as well -- but nothing could be as far from the truth."

Certainly, the NBA hopes so. There could be as many as nine players in the league this season who are 38 years or older: Patrick Ewing (39), Stockton (39), Otis Thorpe (39), Kevin Willis (39), Hakeem Olajawon (38), Terry Porter (38), Karl Malone (38), Sam Mitchell (38) and Jordan.

There is one basketball athlete worth listening to on the subject of Jordan. Kareem Abdul-Jabbar. Like Jordan, he won six NBA titles. He played more minutes (57,446) and scored more points (38,387) than any player in history.

Abdul-Jabbar also played to the age of 41 and saw his production drop dramatically in the final years. His scoring averaged plummeted from 25.9 in 1985-86 to 19.2 in 1986-87. A year later it fell to 14.1 before bottoming out at 11.1 in his final season, 1988-89.

"Personally, I am a skeptic," Abdul-Jabbar said Tuesday. "He had such dominating talent and was an overwhelming player and to come back and play at that level is going to be very difficult in my opinion. I wish him well, I don't think it will work and I hope he gets through in one piece."

Those who think Jordan will succeed usually point to his powers of concentration. As his late father James once said, "What Michael has is a competition problem."

Larry Bird, another fiery superstar who tried his hand at motivating the younger generation of athletes, was constantly frustrated in his role as Indiana Pacers head coach. Will Jordan be able to consistently summon that passion during an 82-game season, one that is sure to have difficult periods given the Wizards' 19 victories last season?

"If he holds up physically, I think the experience and confidence will carry him," said 40-year-old Bruce Matthews, the Tennessee Titans guard who will break Jim Marshall's record of 282 games played this week. "His intense desire -- he was competitive almost to the point of being silly -- makes him so effective.

"When you're tired, you know that you're going to get through it. He's done this thing so many times before. In a sense, it slows down a little bit. My personal opinion is that he's going to do very well. He won't have the reserves he once had, but I believe he'll be able to perform at a high level."

How high, exactly? Most NBA observers concede that Jordan won't be able to match slams with the NBA's young stars like Vince Carter, Allen Iverson, Kobe Bryant and Kevin Garnett.

One NBA head coach, quoted Tuesday by Sam Smith of the Chicago Tribune, voiced the concern of many fans.

"It's going to bother me seeing him if he's the 10th best player in the league," the coach said. "And it will really bother me if he's 25th or 30th."

The fulcrum of Jordan's comeback rests with his knees. He has been bothered by tendinitis in the past and has been icing his knees for years.

"One of the main problems we all face as we get older are problems with our joints, and the ones that are in the worst situations, especially for athletes like Jordan, are the knees," Dr. Jay Olshansky, professor at the school of public health at the University of Illinois-Chicago, told the Tribune. "If he was icing up his knees after every game in his mid-30s, the problem of swelling can only get worse.

"tendinitis, for instance, will get worse. There's very little you can do. There's nothing you can take at this time to increase the cartilage you need to operate those knees as efficiently as when you were younger. If the knees go, you're finished in basketball."

Greg Garber is a senior writer for ESPN.com.