Arroyo was 14-10 with a 4.51 ERA last season. The right-hander was part of a deep group of Red Sox starters and had taken a home-team discount when he signed a three-year contract worth $11.25 million on Jan. 19.
Pena, who can't be a free agent until after the 2008 season, batted .254 with 19 homers and 51 RBI last season and struck out
116 times with 20 walks. A 24-year-old right-handed hitter, he
could play right field instead of lefty Trot Nixon when left-handers pitch against Boston.
Without the 29-year-old Arroyo, Boston still has Curt Schilling, Tim Wakefield, Josh Beckett, Matt Clement, David Wells and Jonathan Papelbon as starters. Arroyo, who pitched five shutout innings
Sunday after struggling in his first three exhibition appearances,
was expected to start the season in the Boston's bullpen.
"They have a surplus of seven starting pitchers in their mind
and I agree," Reds general manager Wayne Krivsky said. "They
needed a right-handed bat to complement Trot Nixon. It all fell
into place rather quickly. [Boston general manager] Theo Epstein
and I have been talking about this for three or four days."
Arroyo had career highs last year with 14 wins, 32 starts and
205 1/3 innings pitched.
"Because we have depth, we might not have been able to get
enough out of him" this season, Boston manager Terry Francona
said, "and that's not a knock on him."
In the past four seasons, Pena batted .248 with 51 homers and
134 RBI with the Reds.
Pena played for the Dominican Republic in the World Baseball
Classic and had four singles in 10 at-bats in three games.
"He's 24 years old. He's just a baby," said Red Sox designated
hitter David Ortiz, who played with Pena on the Dominican team.
"You know this game. It's a learning process."
Pena said he was surprised by the deal. He is still considered a
raw talent but has outstanding power.
"Players with this kind of power usually develop a better walk
rate as they go forward into their mid- to late-20s," Epstein
The Reds freed up salary in the offseason by trading popular first baseman Sean Casey to Pittsburgh for left-hander Dave Williams. Williams has been spotty so far, but still expected to be in the rotation. Aaron Harang heads the rotation and was 11-13 with a 3.83 ERA in 32 starts last year.
The trade also improves the Reds on defense. Adam Dunn can move back to left field, the position that he's played most in his career. Scott Hatteberg, a free agent who played with Oakland last year, will play first.
"Signing Hatteberg was the key" to the deal, Krivsky said.
Arroyo should fit well into that rotation after the trade, which, Epstein said, was difficult "from a personal standpoint.
"I really admire Bronson and have gotten to know him really well," he said, but "if I allowed my personal feelings about a player or recognition that this player would prefer to stay in Boston ... affect our judgment in what we thought was best for the organization, then I wouldn't be doing my job."