BALTIMORE, AUG. 17 -- The Baltimore Orioles' turnstile of a roster continued to rotate at a dizzying pace today, as it likely will do for two weeks. David Segui, a first baseman, and Anthony Telford, a pitcher, reported to the home clubhouse at Memorial Stadium this afternoon, while Randy Milligan went to the disabled list and a handful of his teammates were left with one foot in the big leagues and the other inching toward the next shuttle back to the minors.

Segui's recall from Class AAA Rochester was expected. On Thursday doctors diagnosed a mild shoulder separation that went undetected for eight days after Milligan collided with Oakland catcher Ron Hassey in the opening game of the Orioles' just-completed western trip. He is eligible to return Aug. 25.

The Orioles used five other first basemen on the nine-day trip, ending with the just-promoted Chris Hoiles. Segui, a smooth fielder and switch hitter, was in the lineup tonight, but Manager Frank Robinson said he has promised himself he won't forget about Hoiles.

Segui, the son of former major league pitcher Diego Segui, was hitting .336 for the Red Wings. He went seven for 42 in 12 games with the Orioles in May. He said he was suffering from mechanical flaws in his swing, the result of trying to pull every pitch; ironically, he admits to being in the same rut now.

"I haven't been swinging real good lately," Segui said. "That's baseball, I guess. . . . Hopefully I'll get things straightened out and take advantage of the chance I have to show what I can do. Last time I didn't."

Unlike Segui, the summoning of Telford, 24, was a surprise -- especially to the right-hander who will make his major league debut by starting Sunday in place of Dave Johnson.

He is one of Baltimore's brightest prospects -- a one-time fireballer who refined his style after having shoulder surgery in 1988 and missing 15 months -- but he was at AA Hagerstown and hoping to get here for a brief audition only when rosters expand Sept. 1. His thinking was geared toward next spring, when he may be part of an Orioles rotation that could include no one older than 25.

That timetable was fast-forwarded, however, when team physician Charles Silberstein recommended that Johnson miss his turn to rest his strained lower back.

Telford was a high-strung mixture of excitement and nervousness today as he arrived from the airport, dressed hurriedly and rushed off for his first bullpen throwing session. "I'm speechless," he said, but quickly proved otherwise with a stream of wide-eyed gushing.

Telford was the club's fourth-round pick in the 1987 draft and is the first Oriole since Gregg Olson to jump from AA to the majors. He started this season at Class A Frederick and is a combined 14-4 with a 1.86 ERA at Frederick and Hagerstown; he had 122 strikeouts and 36 walks in 149 2/3 innings.

He had a 90-plus mph fastball before his shoulder problems, but now is a more complete package, with two types of fastballs, a changeup and a sinker. Telford has been on the Memorial Stadium mound before, pitching a complete game for Hagerstown several weeks ago.

But Sunday the opponent won't be Reading (Pa.) -- it will be the world champion Athletics, whom the San Jose native idolized growing up. Telford conceded he'll be nervous -- but not intimidated. "You never know if it's the first and last or first of many," he said. "I'm just going to have some fun and do the best job I can."

Robinson -- committed to a four-man rotation that already includes John Mitchell, Ben McDonald and Pete Harnisch -- said he's not necessarily viewing Telford's outing as a one-time, emergency-only start.

"It could be one time, it could be more," he said. Telford will "be judged on how he does. There's a four-man rotation, and it includes Telford. Right now, it doesn't include Johnson. . . . You can always insert a guy later. That's the easy part."

The tricky part is who will be demoted when Telford is activated. Segui took Milligan's roster spot, so someone will have to be sent down by Sunday. Robinson said he doesn't know who it will be, but said the victim of the shuffling isn't likely to be Ron Kittle, who has a a pulled groin and is without an RBI since July 18.

Kittle isn't sufficiently healed to play the field, but can bat, so won't be disabled, Robinson said. Whoever is demoted should return in September. But more moves are likely before the end of the month.

Second baseman Bill Ripken's stress fracture in his foot is healing quickly; he's due off the disabled list Monday. And pitcher Bob Milacki's strained right shoulder is progressing, though probably not rapidly enough for him to be activated for the upcoming Boston series.