The Road Back Begins in Memphis : Tennis: Michael Chang plays competitively for the first time since his Dec. 6 injury, but the real test is his first singles match tonight.

Robert Kerlan, sports physician to the stars, had seen just about every sprain, strain, bruise, break and tear an athlete could bring him.

Then he saw Michael Chang’s left hip.

Chang, the youngest American male to win the French Open, set another precedent.

Kerlan describes the injury as “almost singular in what I or anyone else have come to expect in a professional athlete. Anything but typical. I’ve seen something like it before in non-athletes--after automobile accidents.”

While chasing a tennis ball during a Dec. 6 practice, Chang cracked the upper edge of the socket that holds the left hip joint together. His twisting motion pulled so strongly that the capsule of the joint split.

It is an uncommon injury, Kerlan says, because the hips of most athletes can withstand such movement. But Chang was susceptible because of unusual bone structure, with the upper edge of the socket--cartilage known as the growth plate--failing to fuse with the bone.

“Unique,” Kerlan says, “in any athlete.”

The rehabilitative process also became unique.

How does an athlete recover from an injury that athletes don’t get?

Kerlan prescribed rest and, later, exercises to strengthen the muscles around the hip. After two months, X-rays indicated enough healing for Kerlan to allow Chang to resume running and hitting tennis balls.

Three weeks later, Chang is entered in the Volvo Tennis/Indoor tournament in Memphis, where he and Jimmy Arias lost their opening-round doubles match Monday to the Uruguayan team of Diego Perez and Marcelo Filippini, 6-3, 7-6 (7-2).

It was Chang’s first tournament match since the injury, but the real test comes tonight when he opens singles play as the second-seeded player behind Stefan Edberg. It is Chang’s first singles match since he came up limping.

Is he coming back too soon?

Chang says his hip still hurts a little.

“Not in the bone or in the joints, but there’s a little something,” he says. “That’s to be expected. My body is recovering from a whole trauma.”

Kerlan doesn’t react calmly when this is relayed by a reporter.

“No, it’s not normal (to still hurt),” he says sharply. “That was one of the things he was advised about. You don’t want him going back out there if he still hurts. Obviously, that would be a little silly.

“But you can never be sure they’re going to do exactly what you ask them to do. With all the pressure on them . . .

“The thinking was that he and I understood what I was talking about. You have to proceed step by step, but you also have to use your head while doing it.”

No one on the Chang team can say it’s too early.

“It’s possible,” says Joe Chang, Michael’s father and coach. “Until you try, you don’t know. There are a lot of ifs with an injury like this.

“I don’t know. I’m not a doctor. I have to play it by ear.”

“I have to listen to my body,” Michael Chang says. “If I feel anything, I’ll have to stop and back off.”

According to Kerlan, the healing process continues.

“By some amount, from a microscopic point of view, it will go on for several more weeks,” he says. “But it’s not critical. To a point, it should hold together.

“But there is no guarantee on these things. If he puts the same force on that area, and there’s no reason to believe it’s stronger than it was before, it could happen again.

“If you can break your leg twice and break your arm twice, it’s possible to fracture your hip twice.”

Chang has been warned about the dangers of coming back too quickly by someone who knows.

Before recently hiring Jerry Solomon as his agent, Chang was represented by Jeff Austin, brother of Tracy Austin, who was perhaps the most striking tennis injury case of the 1980s. Champion of the U.S. Open in 1979 and 1982, back and neck injuries had knocked her all but out of tennis by late 1983.

“When I was with Jeff, he’d talk about how Tracy tried to come back too early and how your body overcompensates,” Chang says. “You need to take the time to be 100% healed and ready to go.”

Still, the Memphis tournament holds a special allure for Chang. Two years ago, he made his professional debut there. He likes the small-town atmosphere and the intimacy of the tournament, held indoors at the Racquet Club of Memphis.

He also is guaranteed a six-figure appearance fee.

It is Joe Chang’s view that Michael has to begin his comeback somewhere, sometime--and Memphis seems as good a place at as good a time as any.

“If we don’t play Memphis, then we’re probably not ready to play Newsweek (at Indian Wells next week) or Lipton (starting March 16 at Key Biscayne, Fla.),” Joe says.

And Michael Chang wants to play in both. Indian Wells is less than a two-hour drive from his Placentia home. The Key Biscayne tournament is a big-money, high-prestige event played amid a Grand Slam atmosphere.

“Hopefully, we’re going to play into it,” Joe Chang says. “We want to build kind of gradually. We’ll see how it goes.”

Chang was granted a first-round bye in Memphis and returns to singles competition tonight against Glenn Layendecker. He used the break in the schedule to team with Arias--no stranger to the comeback trail himself--for the brief doubles tuneup Monday night.

The doubles match served a purpose. “It was good to play to take away some of the nerves going into (the singles),” Chang says.

He admitted to “feeling a bit sluggish” but with just three weeks of practice, he figures that will be the norm for a while.

“They say it takes the same amount of time you’ve been out to get back to where you were before the injury,” Chang says. “If that’s correct, it’s going to take me nine weeks to get back to form. . . .

“I’m a little bit rusty, but I’ve put on some upper-body weight and I’m serving a little bit better. My volleys are a lot better. When my feet come back, everything else is going to come into play.”

That is a pretty big when. Small and slender and only 18 years old, Chang wins because Chang runs. Built so low to the ground, he relies on leg strength for the power he packs behind his ground strokes.

And leg strength is connected to the hip bone.

For better or for worse, the singles comeback begins tonight. Chang insists he will proceed with caution. He claims he won’t push too hard.

He says he will listen to his body. And hope not to hear another crack.