BOSTON -- The Orioles have given up trying to guess when injured first baseman Glenn Davis will be ready to play. The club placed him on the 15-day disabled list yesterday and recalled rookie outfielder Luis Mercedes from the Triple-A Rochester Red Wings.
Davis has been out of action since Wednesday, when he was scratched from the starting lineup with a muscle strain in the rib-cage area below his left shoulder. He was not expected to be out more than a couple of days, but team officials learned last year that trying to speculate on his physical condition is risky.
"I was told two days, then it was seven, and now it will be another seven or more," manager Johnny Oates said yesterday, when the team had a day off in the middle of a three-game series with the Boston Red Sox. "I just don't know."
Davis, reached at his Baltimore home, declined to comment.
Yesterday's move was retroactive to April 7, meaning Davis would beeligible to return next Wednesday.
The injury apparently has nothing to do with the neck injury that forced Davis to miss 105 games last year or the rib-cage strain that sidelined him for two months in 1990, but that is about the only firm conclusion by the club's medical staff since Davis came up sore during the final days of the exhibition season.
He said he first noticed that something was wrong when he was getting off the team flight from Florida ("It felt like somebody shot me in the back," he said). He received a cortisone shot and played through the soreness in the April 3 exhibition game and the season opener April 6, but had medical tests the next day.
The injury was made public Wednesday. Oates had Davis in his starting lineup, but removed him after Davis arrived at the park. The injury was described as a slight muscle strain, and Davis' status was listed as day-to-day, but he did not accompany the club on the six-game trip and will not make the nine-game trip that begins Tuesday.
"From the beginning, I expected it to be a couple of days," Oates said. "That's what he led me to believe. I thought he might be here today and play tomorrow. During his workout Saturday or Sunday, he got out of the pool and noticed a reoccurrence of the spasm.
"I confronted him last night on the phone. I wanted to know when he thought he would be back, and he said, 'I don't know.' So I told Roland [Hemond, general manager] I needed a right-handed hitter, and preferably Mercedes."
Club officials continue to express the hope that Davis will bounce back quickly. Davis was examined last week by team orthopedist Dr. Charles Silberstein, who ran a series of tests and prescribed anti-inflammatory medication and therapy. Davis then sought a second opinion.
The injury still is not thought to be serious, but there is serious doubt that the club can depend on Davis to be a regular this year.
Team president Larry Lucchino is preaching calm. The season is only a few days old, and Davis might miss only 15 days.
"Glenn had an active and productive spring," Lucchino said, "and it's unfortunate that the injury occurred. . . . "We know he wants to get back, and we want to help him get back."
Davis has not played regularly since 1989, when he appeared in 158 games and hit 34 home runs for the Houston Astros. He appeared in 93 games the next season, but still had 22 homers and 64 RBI.
The Astros traded him to Baltimore for Pete Harnisch, Steve Finley and Curt Schilling in January 1991, and the Orioles quickly made him their highest-paid player with a $3.275 million contract.
In his first season with the club, Davis suffered a damaged spinal accessory nerve in his neck during spring training and went on the disabled list April 26. The injury caused his right shoulder muscle to atrophy, and it took more than four months to rebuild it.
Davis returned Aug. 19 and hit five home runs in September, playing well enough to persuade the club to re-sign him for two years at nearly $7 million.
Now, club officials are wondering whether they made the right decision. Oates has spent the past six games playing with a 24-man roster. The Orioles were so short on right-handed depth that they used utility man Tim Hulett at designated hitter twice, but Hulett responded with four hits in eight at-bats.
"I don't think at any one time I have felt we were one player short as far as the 25-man roster is concerned," Oates said, "but we have been caught short a right-handed hitter. Joe [Orsulak] and Brady [Anderson] got us off to a good start, and for a game here and there I'd have no problem with Brady and Joe or Brady and [David] Segui at the top of the lineup. But maybe Mercedes can give us a right-handed outfielder who can hit second and give us a little more speed up there."
Mercedes probably will make his first start Thursday night, when the Orioles face left-hander Joe Hesketh in the final game of the three-game series against the Red Sox.