Glenn Gulliver had spent his entire baseball career in Lilliput. Now that he has been thrust unexpectedly into Brobdingnag, the land of the giants, he is hanging on for the ride.

Gulliver's baseball travels, until last week, were among the little people. He spent seven years in the minors, starting auspiciously in AA ball in 1976 after an all-America senior year in college.

But until this month a major-league uniform never had graced his short and sturdy form, not even briefly in spring training. Gulliver's travels were between AA and AAA. "In 1979 alone I was back and forth five times," he said. Some might have given up.

So who could have been more surprised than he last week when the Baltimore Orioles, having obtained him from the Detroit organization in the spring, promoted him from Rochester to the big club?

In the Oriole clubhouse Gulliver's voice is barely audible, as if he's convinced it was a mistake and that if someone spots him he'll be sent packing back to the little leagues.

The Orioles told Gulliver, 27, not to expect much. "They said they didn't know how much I'd play," said the sandy-haired utility infielder in a whisper.

So he arrived Friday, and Saturday they pointed him to third base. Five days later he had started every game there, been to bat 20 times and managed to reach base 12 times on five hits and seven walks, an on-base percentage of .600.

"He has a good chance to stay around if he just keeps doing like he's doing," said fellow rookie and infield mate Cal Ripken Jr. "Sometimes that's all you need--a chance."

It was Ripken who provided the unexpected opportunity for Gulliver. Ripken joined the Orioles this spring as one of the most highly touted prospects in club history. He was to take over third base, Doug DeCinces having been traded to make room.

But Ripken played third and hit so well that Manager Earl Weaver moved him to shortstop, where Lenn Sakata and Bob Bonner had faltered. Ripken has been almost flawless since.

Weaver tried Floyd Rayford and Rich Dauer at third, then looked over his shoulder and saw Gulliver, batting .303 at AAA Rochester with 82 walks and an on-base percentage just short of .500.

In his fourth big-league game, Tuesday night against California's Dave Goltz, Gulliver showed how he operates at the plate.

First time up he watched four pitches just miss the outside corner. Every one was hittable, none out of the strike zone by more than an inch or two. Four pitches, no swings, man on base.

"My kind of guy," said veteran Ken Singleton, about whom it has been said, "If he don't swing it ain't a strike."

In the fifth inning Goltz evidently figured he had better get the ball over. Gulliver lined the first pitch down the right field line for a double.

"That's the way I hit," Gulliver said. "I wait for the good pitch. That's what Baltimore wants me to do. They didn't want me to take the walks at Detroit. They wanted RBI, but I never could figure it out because they still batted me second."

Bill Lajoie, the Tigers' vice president who signed Gulliver, said the infielder's batting ratio the six years he was in the Detroit organization "was all wrong. It doesn't make sense that a guy got on base the way he did, yet his runs-scored and RBI totals were both low.

"I told him three years in a row, 'Swing on 2-0 pitches and 3-1 pitches.' He's a strong guy; he can hit the ball."

Lajoie thinks the majors, in which pitchers have better control, might be good for Gulliver: "With his batting eye, he gets more good pitches to hit."

Gulliver's statistics paint an uninspiring portrait of a plugger with a penchant for drawing walks. Professional career batting average: .267. On-base percentage: .418. Asked to assess his fielding, he stammers a bit: "I don't know how to answer that. I've always been a pretty good hitter and that's the reason Detroit kept me around." He isn't particularly fast and his best home run total was 12 in 76 games this year at Rochester.

Which provides even more reason to gather around a career minor leaguer who bursts into the majors like a freshly lit sparkler. You never know how long it will last.

"I just want to do good enough to stay," Gulliver said in his softest voice, lest anyone hear. "That's my thing. Just to stay here."