A day in the life of Sammy Stewart, the most versatile relief pitcher in baseball, as well as one of the best, includes many things.

In the bullpen, he practices juggling a baseball, Harlem Globetrotter style, bouncing it off all portions of his body, catching it in the crook of his elbow, and, finally, making the ball disappear into thin air.

Stewart is convinced that someday, with a big lead in the seventh game of the World Series, the national TV cameras are going to be focused on him. He wants to be ready with something just a little bit different.

The right-handed Stewart also works on his sweeping left-handed curve ball. He's already used it once for the last strike of a game. Well, sort of. Unfortunately, the left-handed hitter bailed out of the box in mid-Stewart windup.

"A lot of managers might have gotten real upset about that pitch," drawled Stewart, who was reared and still lives in Swannanoa, N.C., "but Earl (Weaver) lived up to my expectations (of him). He said, 'That's why I still enjoy comin' to the ballpark. You never know what the hell you might see.' "

Stewart, who had a 1.58 ERA in 97 relief innings last year, already is planning his next test of Weaver's patience and depth of perception: "We'll see what Earl says when I sneak over to his house in Perry Hall and steal some of his tomatoes."

When Stewart isn't serenading his teammates with bluegrass ("In the pines . . . "), rock 'n roll ("I'm not your steppin' stone . . . ") or punk rock (a Joan Jett album hung in his locker for a whole season), he's committing anecdotes to memory for what he threatens may be the great comic baseball autobiography.

"I just love to listen to these guys," he said. "The other day, Earl says to Jim Palmer, 'The ball's really juiced up this season.' So, Cakes (Palmer) says, 'Is that why our popups are going higher this year?' "

And, for better or worse, Stewart thinks he's the first pitcher ever to go into a stretch with both hands above his head; this is, to say the least, a unique approach.

Also, Stewart has invented a new "inside-out" pickoff move to second base that needs no pivot, just a flick of the wrist; already, in a season and a fraction, Stewart has picked 10 runners off second with it. That is, when he hasn't thrown the ball into center field.

"When I first came up (in 1978), I was real loose and real hyper (excited)," said Stewart, who struck out a major league record seven consecutive batters in his first game. "Now . . . (pause, big crazy grin) . . . I still am."

More than anything else, Stewart's life contains a delicious uncertainty. The handsome 6-foot-3 Stewart, with his mane of curly, black, Elvis-length hair, never knows how, when or if he'll be used.

Perhaps alone among big league pitchers, Stewart is constantly on call. As the premier long reliever in the game over the past three seasons, Stewart begins loosening himself when the first opposing batter of the game steps to the plate. Half of his 26 relief appearances in '81 came in the fifth inning or earlier. He even pitched 8 1/3 shutout relief innings in one winning stint.

"I have to be ready right away, so I do stretching exercises. But, if I see one-two-three (in the first inning), I just sit down and start tellin' stories." Or cheerleading. Stewart is in charge of the bullpen's confidence, for instance, telling Don Stanhouse as he warms up, "Stanley, your slider looks astounding. You'll dazzle 'em."

Stewart expects the same upbeat assistance in return. "When you're warmin' up, if you don't feel good, you don't even want to come out. But once you get to the mound, you gotta be confident." When the Orioles' new catcher, Joe Nolan, visited Stewart recently and informed him that his fast ball wasn't very fast, Stewart showed rare anger, snapping, "Don't ever tell me that. Tell me, 'Come on.' "

Stewart's semireadiness throughout a game never stops. The first time he warms up, it's a full-scale project. "I like to take my time . . . I hate to see a guy start throwing from 40 feet. Start from the rubber. Don't short-arm it. Use a long, natural motion." Once, he's warm, Stewart can get back up in another inning and be ready in a dozen pitches or fewer. Then he's analyzing, "What is my best pitch tonight? Is every fast ball sailing? Is the slider the best? Pitching is making the hitter change the last six inches of his swing."

In the late innings, Stewart's still liable to receive a phone call. He never panics. His rookie year he learned the lesson: "Don't worry yourself to death. Go out there and act like you've got a 10-year contract."

On top of all this, Stewart never knows when he may be asked to start a game. He has "found the balls in his shoes" 14 times as an Oriole starter, including Friday night in Seattle when he left in the sixth inning ahead, 9-4. The Orioles won the game, 11-4. His record as a starting pitcher is 6-6, with a 3.82 ERA, compared to a overall ERA of 3.24.

It's typical of Stewart's gung-ho attitude that last Oct. 2, with the AL ERA title secured, he started a meaningless game because older pitchers were tired and ready for vacation. Stewart got routed, sending his ERA up from 1.95 to 2.33. Then, to top off the injustice, Stewart got hornswoggled out of the ERA title by a fraction of a percentage point on a "round off to the nearest inning" technicality that was so blatantly stupid that, a month too late to help Stewart, the rule was changed. But not retroactively.

His whole career, Stewart has gotten the short end of the stick--been exploited, some might say--because of his sweet disposition and willingness to be used in any old way if it helps others.

Ideally, Stewart says he needs one day's rest if he pitches one inning, two innings require two days and three or more, like a start, need three days.

What makes Stewart different, and inordinantly valuable, is that he can break all his rules. Weaver has used Stewart the way Americans used gasoline--like it was an inexhaustable resource. "Stewart warming the bullpen," is an echo in Memorial Stadium. "Every day, you come to the park thinking, 'I'm going to be up today,' " Stewart said. "After using all that mental and emotional energy, if I don't get in, I'm a little disappointed. But you just have to carry that enthusiasm over to the next day."

If Stewart got a career-ending sore arm tomorrow, only one diagnosis would be possible: burned out. Recently, after Stewart had thrown 128 pitches in a nine-plus-inning start, Weaver called him back to lose in relief with just two days rest. Stewart didn't complain.

"I think I've got a perfect reliever's temperament and I've got a rubber arm," said Stewart, speaking metaphorically, "although sometimes I think a 'rubber arm' just means that you don't baby yourself."

Stewart has been babied less than any pitcher imaginable. Most players like to be paid in money; Stewart, who is signed through '82 and who will not be eligible for free agency until the winter of '84, has, to a large degree, been willing to accept Weaver's praise and his teammates' affection in its place.

This spring, Stewart has, for the first time, seemed confused by the anxiety surrounding his multiple, and ill-defined duties. His record is a bland 3-2 with a 4.10 ERA; he also has one save, two "squanders" and an excessive 20 walks in 37 1/3 innings. "When Sammy says he feels good, I feel good," appraised Weaver. "But right now, I don't feel so good."

Currently, Stewart is the least of the culprits in an Oriole bullpen that has turned into a doghouse.

"On most teams, it might be Panic City right now, and I'd be saying, 'Hey, I want to start,' " said Stewart. "But not here. Why not give Earl the benefit of the doubt? Stick with what we got. My time will come."

The latest twist in the Stewart saga has come in recent days. With veterans Steve Stone and Jim Palmer both injured and disgruntled (as they've been since last season) and both asking to be traded, Stewart has become a starter.

Will this be the first step of a Stewart escape from the 'pen? Or, as has happened several times in the past, will a Stewart failure as a starter, or a return to "health" by Palmer or Stone, return Stewart to his limbo?

Stewart knows long relief is the dead end of pitching. Everybody tells him he's too good for it, even if he is the glue that holds together an aging staff. "In July and August, if Earl sees those starters are going good, maybe he can use me more in short relief," said Stewart, hopefully.

So, for the time being--an ambiguous "time being" that now is in its fourth season--Sammy Stewart will do the dirty, career-endangering job he's done for so long.

His teammates worry about Stewart, how he may never find his niche, never really discover if he's a short man, a starter or just a wonderful, bizarre "long man." They worry that his rubber arm will turn to stiff plastic before he gets a chance at a big free-agent contract, that all his devoted, selfless love of the Orioles will only get him a bum arm and an early exit from a game that should value a commodity as precious and rare as a Throwin' Swannanoan. For the next few days, or weeks--however long his trial period in the rotation lasts--his teammates will be rooting for him to make his great breakout.

Stewart himself has time to contemplate all these long thoughts of a long reliever in his bullpen hours. What notion drifts up in his troubled brain?

"Sometimes," he said, brow furrowed in thought, "I just think about how great it is to get to be a ballplayer."