01:00 AM EST on Tuesday, March 21, 2006

BY SEAN McADAM
Journal Sports Writer

FORT MYERS, Fla. -- Supply and demand intersected yesterday to produce the first significant trade of the spring for the Red Sox.

Armed with an excess of starting pitching but lacking much power in their pipeline, the Red Sox shipped Bronson Arroyo to the Cincinnati Reds in exchange for outfielder Wily Mo Pena. The Red Sox also sent approximately $1.5 million in cash to the Reds, or the difference between Pena's 2006 salary ($1.25 million) and Arroyo's ($2.75 million).

Pena will platoon in right field with Trot Nixon this season and present the Red Sox with some leverage at the position as Nixon nears free agency. He'll be eligible to leave the Red Sox after this season.

At 24, Pena already has spent parts of four seasons in the major leagues. He possesses extraordinary power (26 homers in 336 at-bats in 2004; 19 homers in 311 at-bats last year), but also has shown himself to be prone to strikeouts. Last year, for instance, he struck out 116 times in those 311 at-bats while walking just 20 times.

His offensive profile hardly fits what the Red Sox typically seek in players.

"We still value on-base percentage tremendously," said general manager

Theo Epstein. "But we've never been stubborn about it. There's more than one way to be a good offensive player.Even with his strikeouts now, he's still a really dangerous threat against left-handed pitching. Not all players control the strike zone as well as they might (later in their careers). But players with this kind of power usually develop a better walk rate as they go forward into their mid- to late-20s."

Ever since Wayne Krivsky was hired as general manager of the Reds in February, the two clubs had been engaged in trade discussions.

Initially, the Sox inquired about Austin Kearns, but the Reds wouldn't part with him. That led the two clubs to focus on Pena.

The Sox' three highest-rated outfield prospects -- David Murphy, Brandon Moss and Jacoby Ellsbury -- don't project as power hitters, and the Red Sox thought they needed to obtain some production to help them now and into the future.

"We don't have a true home run hitter, per se, in our minor-league system," Epstein said. "As you look ahead, it's nice to have someone in the organization who has a chance to develop middle-of-the-order power."

But the Sox also expect some more immediate dividends.

"We like his ability to hit left-handed pitching and his ability to add power to the lineup and the bench," Epstein said.

Despite his hulking size -- 6-foot-3, 230 pounds -- Pena runs well and has an above-average arm and is athletic enough to play center field. In addition to platooning with Nixon in right, he can fill in for Coco Crisp in center and Manny Ramirez in left.

His arrival may force Dustan Mohr out of the roster picture, since Mohr had been the favorite to start the season as Nixon's platoon partner in right.

In the future, Pena could see some playing time at first, a not insignificant short-term factor since the Sox remain worried about third baseman Mike Lowell's slow bat. If Lowell continues to struggle, the Sox may be forced to shift Kevin Youkilis back across the diamond, opening up potential playing time at first for the team's newest arrival.

At age 17, Pena was the subject of an intense bidding war before signing with the Yankees. Two years later, he was sent to the Reds in exchange for Drew Henson, the former Michigan quarterback who never panned out at third base.

Epstein pointed out that because of his original contact, Pena "had to be in the big leagues since 21, getting irregular playing time when most players would have been developing (in the minor leagues). He hasn't had time to develop."

The trade of Arroyo, meanwhile, was exactly what the pitcher's agent, Gregg Clifton, warned might happen when Arroyo, against Clifton's advice, agreed to a below-market three-year, $11.25-million deal in January.

That deal, with its cost certainty, made Arroyo attractive to small-market teams such as the Reds, precisely the scenario Clifton feared. At the time, Arroyo said co-GMs Jed Hoyer and Ben Cherrington told him they didn't foresee him being traded.

But Epstein denied that the Red Sox went back on their word in dealing Arroyo.

"I can assure you there was no handshake, no gentlemen's agreement," said Epstein. "I think all our players understand that without an express no-trade clause, we can't give them any guarantee that they won't be traded at a certain point."

Epstein saluted the contributions made by Arroyo, who was claimed off waivers from the Pittsburgh Pirates in February of 2003.

"From a personal standpoint, I really admire Bronson," said Epstein. "I've gotten to know him really well, and that made it difficult. From an organizational standpoint, we owe a lot to Bronson. We owe him a huge debt of gratitude. I think it's safe to say we wouldn't have won the World Series without him. He handled himself with professionalism and class, on and off the field, throughout his time with the Red Sox.

"That said, if I allowed my personal feelings about a player to affect our judgment and what we thought was best, then I wouldn't be doing my job."

The Sox entered spring training with seven starters -- Curt Schilling, Tim Wakefield, Josh Beckett, David Wells, Matt Clement, Jonathan Papelbon and Arroyo -- and were in a position to deal from strength.

"I still think we have tremendous pitching depth," said Epstein.

And if not?

"By the time we get into July, August and September," he said, "someone will emerge if we need it."

smcadam@projo.com / (401) 277-7340