"He's a good offensive player and he's a good defensive player," said general manager Walt Jocketty. "Right now he was the best offensive player we felt we could acquire."
Both players were surprised by the deal, and in fact Luna played the eighth and ninth innings of the Cardinals' game against Chicago after the deal had apparently been agreed to.
"I'll go to St. Louis, it's a good city to play ball in," Belliard said. "I'll try to help them win the division. I know I'm going to make friends over there, but I have a lot of friends here. I feel good about them, and I know they feel good about me, so it's hard for me. I didn't think they'd trade me."
Luna was close with a number of Cardinals players, particularly superstar Albert Pujols, and was definitely caught off guard by being sent to Cleveland. He came up through the Indians organization before St. Louis took him in the Rule 5 draft before the 2004 season.
He's expected to contend for the starting job at second base with the Indians.
"It's a good opportunity," Luna said. "I'm hoping to play every day in Cleveland."
Second base has been a problem offensively for the Cardinals this year. Luna put up solid offensive numbers in limited duty, but his inconsistency at the plate and in the field left the club nonplussed. Aaron Miles received the majority of the playing time at second base while Luna played a variety of positions. Belliard, meanwhile, will become the everyday starter.
Entering Sunday's games, Cardinals second basemen ranked near the bottom of the National League in nearly every offensive category. They were last in slugging (.364) and home runs (four), tied for last on runs scored (15), second-to-last in on base-plus-slugging (.702) and tied for 14th among 16 teams in RBIs (35).
Belliard thus represents an instant upgrade offensively from what the Cardinals had been getting.
The difficulty comes in parting with Luna, who in part-time duty at multiple positions had come close to Belliard's offensive abilities in 2006. He put up a line of .291/.355/.417 prior to the trade. He was erratic in the field, however, and manager Tony La Russa always maintained that he wanted to see Luna take more consistently good at-bats.
"I don't think anybody has more confidence in [Luna's] ability than we do -- not just I, but our staff," said La Russa. "And he's rewarded us with being a really good player. But the scouts that had been watching gave Walt the report that Belliard is more ready right now to be a complete player, and he would improve our chance to win."
Jocketty acknowledged Luna's potential, but nonetheless pointed to the offensive upgrade in the short term. Luna cannot be a free agent until after 2010, while Belliard is eligible for free agency this winter.
"[Luna was] a guy we had control of, and he's a guy that we hoped would step in and play second base this year," Jocketty said. "But he didn't develop into that, so we felt we had to try to upgrade.
"If you're going to improve your club, you have to trade something. You generally have to give up guys that you control longer than the guys you acquire."
Belliard had battled a sore hamstring recently, causing him to miss six games. But he played the last two games, and the Cardinals are confident they are acquiring a healthy player. Belliard is expected to be available for the club's next game, Tuesday night against Philadelphia.
"The thing that has always been impressive about him is that I've seen him rise to the occasion in winning situations," La Russa said. "He doesn't hide from them. He charges them. That's the thing I remember the most about him."
Second base had been one of several areas where the Cardinals were interested in an upgrade. They had interest in Carlos Lee and Bobby Abreu, both of whom have been moved in the past few days, but never got close on either outfielder. They remain in the hunt for one or more relief pitchers, an outfield bat and possibly a starting pitcher.