As he walks through the Baltimore Orioles' locker room these days, Joe Altobelli has to stay on his toes. Well, on one toe, anyway.

The heel of his left foot has had a painful, open infection for considerably more than a month. Orioles' players do a funny but sympathetic imitation of Altobelli's weird gait.

The man's-man manager hates to give in to pain, so he's developed a short-leg shuffle of a walk that disguises his discomfort so that few outside the team even know that he's in constant nagging pain.

Perhaps that is what Altobelli has done best all of this season: hide his pain, his discomfort, his worry.

Few managers go through a season of more constant annoyances, prickly embarrassments and general perturbation than Altobelli has endured.

Yet his Orioles enter the head of the stretch with a four-game lead in the American League East and the best record in baseball.

Altobelli's various forms of suffering began almost immediately and have seldom relented.

If a previous Baltimore manager had endured the tests that Altobelli has surmounted, his legend would have another chapter.

"You mean they'd be calling him a genius?" says Altobelli mischeviously.

The full list of Altobelli aggravations--physical, psychological and team-related--would be prohibitively long, but a synopsis gives the gist.

Soon after being appointed manager, Altobelli fell backward from a dais and hospitalized himself with severe contusions. Then, in midseason, he went through a month-long bout with a mystery disease that afflicted him with chills and fever, body aches and awful headaches. "The players call it my Star Trek disease," says Altobelli. "You know, 'of unknown origins,' a disease no man has ever had before . . . After the medical advice I've gotten this year, I think I'll just go to a witch doctor in the future."

His team's health has been as bad as his own. At one point, the Orioles had five players on the disabled list. The team's three best starters of '82 have all had disastrous seasons. Mike Flanagan missed 15 starts with a knee injury, Dennis Martinez has been inexplicably abominable (the team is 6-16 in his starts) and Jim Palmer (3-4 with 20 missed starts) has surpassed all his previous records for mysterious injuries, contract disputes and dissension-making mischief.

"I've found that when you talk to Palmer, you do a lot of listening," said Altobelli, with a tight jaw.

At one point, Altobelli had to persevere with a rotation that included Allan Ramirez, Paul Mirabella, Storm Davis and rookie Mike Boddicker. The club's star reliever, Tippy Martinez, used the All-Star break to have an emergency appendectomy that sidelined him a month.

"In this game, a lot of water has to go down your back," Altobelli said.

Two of Altobelli's players were questioned by the FBI in a drug probe. His long reliever, Sammy Stewart, was charged with drunk driving.

With all these crises, it's no surprise that the Orioles have had not one but three potential season-killing slumps--0-7 in May, 5-12 in June and 0-7 in August. Once, at the nadir of a seven-game losing streak, Altobelli was reduced to calling up an AAA pitcher, Bill Swaggerty, to start against the formidable White Sox. "The thing I don't want to do is panic," said Altobelli then, his concern genuine that he might lose his grip on himself and his team.

Midseason rumors flourished, though team owner Edward Bennett Williams denies them, that Williams put out feelers to Earl Weaver to see if he would return to manage the rest of the year out of loyalty to a desperate franchise.

When Altobelli was booed in Memorial Stadium, or second-guessed in the media, he was characteristically stoic.

"The most dangerous people in the world are the ones who think they're smart," he said of his over-the-shoulder critics. At the occasional hometown boos, he just laughed dismissively, saying, "That's nothin'. One time, in Rochester, I had to get thrown out just to escape 'em."

Now, it's September.

The Orioles not only have their sport's best record--and a streak of 17 victories in their last 21 games--but they've also outscored their opponents by 129 runs, a margin of superiority comparable to the 100-victory Orioles teams of '79 and '80.

The Orioles also lead the majors in runs per game and homers, and are ahead of the franchise's all-time run-scoring pace. The Orioles, 19th in the majors in team ERA in '82, now have the second-best ERA in the American League, despite the worst season of arm injuries in club history. For spice, they have their league's best road record and best winning percentage on artifical turf.

Altobelli probably has nothing to do with all this. At least that's what he'd have the world believe. Seldom has a team wanted praise, and felt it to be so overdue, as these Orioles. That's why Altobelli is such an appropriate manager. What he does best is avoid credit.

When recently the Orioles almost miraculously won four late-inning games, with many of Altobelli's moves working in a pinch, the manager said, "I get here every day at 1:15. Maybe I oughta wait and just get here in the seventh inning . . . These guys are something. I'm with 'em. They never say die."

Good old Joe, just along for the ride. Prodded for a quip, Altobelli won't even invade that player sanctuary. "What did John (Lowenstein) say?" he will ask, aware that Lowenstein is proud of his one-liners. "If John doesn't have an answer, there isn't one."

Altobelli even conveys the impression that he expects his players to teach him about how to perform well under September pressure. He makes no pretense that he is doing any pennant-race teaching.

What Altobelli does well, and it seems to suit these Orioles well, is set a tone of patience and goodwill. He scoffs at the whole premise of brilliance.

"We think we're so wise," he says. "We'll look like clowns in 20-30 years."

The Orioles liked Altobelli even before he arrived, but, through a season of relentless hardship, they have grown to respect him.

"This is the easiest club to play on that I've ever seen," says Tippy Martinez. "We have fun. We can stink worse than anybody you ever saw, but we don't care. Joe makes it easy. This team has always been able to laugh, but now the manager laughs, too."

Yet, he is that indefinable thing: "a good baseball man." Altobelli trusts his instincts on when to relieve pitchers; Weaver never trusted his and always fell back on statistics or theories or pitch charts or radar guns.

Altobelli can plan out the use of a pitching rotation and a bullpen weeks in advance, then stick to his guns--keeping all hands rested and strong--where Weaver couldn't bear to see one game lost and, so, sometimes made too many moves, exhausted too many arms.

For Altobelli, this September could be the most glorious, or the most cruelly unfair, month of his third of a century in baseball. He'll endure pressure he's never known. His split-second decisions--not his specialty--will be under a microscope.

Altobelli knows he's on probation. Owner Williams was a Weaver worshipper and prefers aphorisms to malaprops from his managers. "I've only had my feet up on my desk once this season," says Altobelli, "and darned if that wasn't when Mr. Williams walked in."

This week, Williams said, "If we had a third baseman and a right-handed short reliever, we'd rule the world . . ."

Told about the owner's assessment of the team's needs, Altobelli said, "He didn't say anything about a manager did he?"