FORT LAUDERDALE, Fla. -- The Orioles and Marlins traded spare parts on Wednesday, when Baltimore sent right-hander Hayden Penn to Florida for shortstop Robert Andino. Both Penn and Andino are out of options and would've faced an uphill battle to stick on their previous team's roster.

Andy MacPhail, Baltimore's president of baseball operations, said that he began shopping Penn in recent days. The Orioles had originally been inclined to break camp with a 13-man pitching staff, but with Andino in tow, they'll likely head north with a seven-man relief staff and four dedicated position players on the bench.

"When it became evident he wasn't going to break with us, we were pretty much looking at exposing him to waivers," said MacPhail of Penn. "We didn't think he would clear, so we called clubs that we knew had had an interest over the last couple of years and had inquired about him. I happened to be sitting next to [Marlins president of baseball operations] Larry Beinfest [on Tuesday], and he asked about him. So one of the calls we made was to Larry asking if he had interest, and he did."

Beinfest had a roster problem of his own. The Marlins have one of the league's best young players in shortstop Hanley Ramirez and also had a crowded battle for a utility slot. Moving Andino made sense for Florida, and a deal was quickly hammered out between the two teams.

Baltimore had been toying with the idea of letting utilityman Ryan Freel handle reserve duties at shortstop, but that project stalled during Spring Training. Andino, a career .258 hitter in the Minor Leagues, gives the Orioles a true backup to Cesar Izturis and rounds out the team's roster two days before the end of Spring Training.

"If I had the opportunity to get a 24-year-old bona fide shortstop that can play defense, it was really something I can't pass up," said MacPhail. "He's going to get more opportunity to play now because he's not behind Hanley Ramirez. I'm sure we're going to get an opportunity to see him more, move him around.

"But the attribute that was attractive to us was the defensive ability to play up the middle."

Penn, meanwhile, represents the end of a heralded prospect's rise through Baltimore's organization. The former fifth-round draftee shot through the lower levels of the team's farm system and became one of just two Baltimore pitchers since 1967 to make his Major League debut before their 21st birthday.

That initial promise went unfulfilled, though. Penn struggled in the big leagues and came down with a case of appendicitis in 2006 on the day he was scheduled to make his season debut. Several pitchers leapfrogged him in the organization, and Penn wound up struggling to reestablish himself over the past two years.

"Someone wants me. I'm excited to go over there and pitch," he said. "I've had a good time here [and] made a lot of good friends here over the years, but I look forward to a new start there. I really do. I think it will be good for me and I'm excited. Somebody wants me and they traded for me. Hopefully I get that opportunity and pitch well."

The addition of Andino likely ends the roster bids of veteran shortstops Chris Gomez and Jolbert Cabrera. Baltimore also has its pitching staff clarified, meaning that right-hander Brian Bass is now the man on the bubble. As of now, the O's bench appears to be Andino, Freel, Ty Wigginton and a backup catcher.

"We're too thin in the middle infield in terms of who can play defense there," said MacPhail, summing up the trade. "That was an area of need for us. We've known Andino. [Scouting director] Joe Jordan knew him from his role in the Marlins organization. Rick Kranitz knew him when he was the pitching coach over there.

"We felt like he really solved an issue for us in terms of the final composition of our team. It came together in a very short period of time. It was just a matter of getting the medical records and talking to the players."