As expected, the Baltimore Orioles got down to a 24-player roster today by placing third baseman Floyd Rayford on the 15-day disabled list.

Rayford has bone chips in his left thumb and was supposed to test the injury today before the Philadelphia Phillies beat the Orioles, 4-2, in their final exhibition game of the spring.

But by the time the team's bus arrived at Jack Russell Stadium, Manager Earl Weaver had decided to take the safest course. The move can be made retroactive for up to 10 days, but a player is required to miss at least six days of the regular season, meaning Rayford can't play before the Orioles' April 13 game at Texas.

"I think it's best that he not do anything," Weaver said. "Why . . . would I want him to come out and get it hit by a throw and mess it up even more. For another thing, he's missed five or six days of hitting. We hope he can start taking batting practice by Wednesday and be ready to play Sunday."

Rayford hopes he'll be ready by then. He was injured March 28 at Fort Lauderdale when a Mike Flanagan pitch caught him on the thumb, and he has done only a little hitting since.

Doctors want to remove the chips after the season, but have said the chips should calcify in the next few days, allowing Rayford to play.

Rayford hopes so. He was the Orioles' leading hitter in 1985 (.306) and was supposed to be in an Orioles' opening day lineup for the first time this year. There also are financial considerations. He has a $310,000 contract for 1986, but receives another $40,000 if he plays in at least 140 games.

"I don't want to go on the DL," he said, "but it has been bothering me. I'm a little worried about it, but the doctors tell me it'll get better pretty soon. What bothers me is the matter of time it'll take to come back."

With Rayford out, Weaver said he'd probably start Jackie Gutierrez at third and is leaning toward using John Shelby in left field and Mike Young as designated hitter.

Placing Rayford on the disabled list allows the Orioles to wait at least a week before making their final roster decision, although designated hitter Larry Sheets is the likely choice to go to Rochester.

Ken Dixon, making his final start before pitching the third game of the season, allowed three hits and a run in five innings . . . Eddie Murray had an RBI single and Cap Ripken tripled and scored on Fred Lynn's double . . . The Orioles won nine of their final 12 spring games to finish 14-15.

Orioles first baseman Eddie Murray has never won a most valuable player award, but he has a couple of MVP distinctions: only he and the New York Mets' Keith Hernandez have been mentioned on MVP ballots for all six seasons in the 1980s. Further, Murray has more votes than anyone. Hernandez is second.

In a study of 264 players, Detroit reporter Vern Plagenhoef found that Baltimore's Lee Lacy is the leading right-handed hitter of the 1980s at .3065.