SARASOTA, FLA., FEB. 19 -- Jim Palmer's bid to become baseball's first active player in the Hall of Fame edged closer tonight. According to sources close to the situation, the Baltimore Orioles are set to invite the 45-year-old pitcher to spring training as a nonroster player.

Only a few contractual details -- and a final okay from Palmer -- were still to be worked out, but sources indicated a formal announcement on this most improbable of comeback stories is expected Wednesday.

Barring a last-second problem, Palmer will report to camp on Thursday and join Friday's first workout at Twin Lakes Park here.

He will be a nonroster invitee and won't actually sign any contract unless he makes the 25-man roster. His agent, Ron Shapiro, apparently was also negotiating a safety net to allow Palmer to return to his broadcast duties with WMAR-TV-2 for play-by-play work on as many as 50 Orioles games.

Palmer wasn't available for comment. He was en route from Chicago to Baltimore to review the contact and make a final judgment on whether or not to resume his baseball career.

Last night the Orioles clearly had decided to extend him an invitation to spring training, and it appeared he was ready to grab it.

"We're still working at it," Shapiro said. "It's not a done deal yet, but it's closer than it was 24 hours ago. He definitely wants to play and we're trying to work on some things."

Orioles officials would say only that negotiations were ongoing. Since Palmer first announced his intention to return to baseball late last year, they've monitored his work with interest and discomfort.

The source of the discomfort was in not wanting to snub one of the greatest Orioles of all time, a 268-game winner who passed up several chances to leave Baltimore for more money.

But almost no one in the organization believes he'll make the team. He says he's throwing in the 85-mph range -- about the major league average -- but scouts say it has been closer to 80.

Baltimore's minor league pitching instructor, Dick Bosman, said after watching Palmer throw batting practice last week that he saw a below-average fastball but a surprisingly good curveball. But he refused to speculate on Palmer's chances, saying: "Don't ask me if he can get major league hitters out, because I don't know."

Then there's the matter of what to do if he's ineffective in spring training but doesn't want to retire. He and the Orioles were bitter over the way his career ended a few weeks into the 1984 season, with him saying he wasn't wanted and club officials saying they were tired of his complaints about his health.

Last night, club officials were considering the positive side, which is that so much attention will be paid to him this spring that youngsters Ben McDonald, Mike Mussina, Arthur Rhodes, Leo Gomez and Mike Linskey might be able to work in obscurity.

If Palmer does makes it back, it would be an unprecedented comeback. He won a club-record 268 games and three Cy Young awards in his 19 seasons with the Orioles, winning 20 or more games eight times and pitching four pennant-clinching games between 1966 and '71.

Yet he was remarkable as much for his idiosyncracies as for his pitching proficiency, with his feuds with longtime manager Earl Weaver and his penchant for discovering injuries, legitimate or otherwise.

Still, he was a favorite of the Orioles' late owner, Edward Bennett Williams, who hoped Palmer would stay with the organization. Williams once said Palmer could eventually have almost any job, especially pitching coach or manager.

Staff writer Mark Maske contributed to this report.