ST. LOUIS -- Shortstop Jack Wilson is about to make his first significant stride toward returning to the Pirates.

Or, as he exclaimed upon getting the news last night in Bradenton, Fla., "Finally!"

Wilson, out since April 3 because of a strained left calf, is scheduled to join Class AA Altoona tomorrow for its 10:35 a.m. home game against Akron, about four days earlier than expected. He will need to play about a week's worth of games with the Curve.

On that timetable, Wilson would be back with the Pirates as early as May 23 to open a home series against the Chicago Cubs. His original target date was May 27. But, as everyone involved continues to stress, all dates are highly tentative.

Wilson's rehabilitation work in Bradenton has been seamless the past two days, notably his defense, prompting him and management to accelerate his timetable slightly.

The Pirates promoted reliever Marino Salas from Class AAA Indianapolis -- and added him to the 40-man roster -- to fill the vacancy left by the Monday optioning of John Van Benschoten.

For Salas, one of two relievers general manager Neal Huntington acquired from Milwaukee in the Salomon Torres trade Dec. 7, the experience in Major League Baseball is his first. He pitched only 14 games above Class AA in the Brewers' system.

"I'm very excited, very happy," he said.

Salas, 26, had a 0.77 ERA and struck out 20 in 23 1/3 innings, a performance that he and others are partially crediting to Indianapolis pitching coach Ray Searage and minor-league pitching coordinator Troy Buckley. Searage and Buckley helped Salas restructure his mechanics, with an aim of keeping all four pitches -- an unusually rich arsenal for a reliever -- down in the zone.

"I had a lot of help," Salas said. "Ray really helped me."

The 40-man roster is at 39.

Huntington acknowledged it was a "very tough decision" choosing between Salas and Jesse Chavez, Indianapolis' other standout reliever. Chavez has a 1.61 ERA and 23 strikeouts in as many innings.

Management's thinking was that Chavez, who had a similar level of adjustment made to his delivery, could use more time for repetition.

• Huntington said the fate of Rule 5 draft pick Evan Meek will be determined today. The Pirates and Tampa Bay, Meek's original team, are trying to work out a trade that would keep Meek in the Pirates' system. If not, the Rays could reclaim him for $25,000.

• Long relief duties will be shared by Franquelis Osoria, Sean Burnett and Salas. "All of them can go multiple innings," manager John Russell said.

• Altoona reliever Ronald Belisario, a member of the 40-man roster, has been shut down because of inflammation in his right hand, the result of some wear from the split-fingered fastball. He should return soon.