It's an opportunity for Eckstein -- who hasn't seen as much playing time over the past two months with the Jays -- to see the field more often, and to do so with an Arizona team that has designs on a trip to the postseason. In return, the Blue Jays received Minor League pitcher Chad Beck, who will report to Class A Dunedin.
"I'm happy for him," said Blue Jays manager Cito Gaston, referring to Eckstein. "This man is probably one of the classiest individuals I've ever had here. He never complained once. He came to play. Any time I asked him to play, he played. If he didn't play, or I put a defensive player in for him or whatever, he never said a word.
"All he wants to do is win. I'm happy for him. I think it's good for him. He's going to go to a first-place team and get a chance to maybe play in the playoffs."
The move comes one day after Toronto announced that it had dealt veteran outfielder Matt Stairs to the Phillies in exchange for a player to be named later. Both Stairs and Eckstein are now eligible for inclusion on potential postseason rosters with their new employers.
The Diamondbacks were in need of infield help after losing second baseman Orlando Hudson to season-ending surgery on his left wrist. Eckstein can provide some veteran help for Arizona, which has used Augie Ojeda and Chris Burke at second. This season, Eckstein has started five games at second base -- a spot he hadn't manned since 2001.
Eckstein already has two World Series rings to his credit: one with the Angels in 2002 and another with the Cardinals in '06. The shortstop was hoping he'd have a shot at a third with the Jays this season, but he's ready to move that goal to the desert.
"The ultimate goal was to try to bring a championship here to Toronto," Eckstein said. "So in that sense, it's very disappointing. Now, having the opportunity to go to Arizona, it's nice."
The 33-year-old Eckstein was signed to a one-year contract worth $4.5 million over the offseason to serve as Toronto's starting shortstop. Under former manager John Gibbons, Eckstein started 47 of 74 games at short, missing 19 games between May 7-27 with a right hip flexor injury.
When Gaston took over as manager on June 20, Eckstein was relegrated to a bench role, while infielders John McDonald, Marco Scutaro and Joe Inglett assumed most of the innings up the middle. Under the circumstances, Eckstein said he understood that being traded was certainly something that could happen this year.
"I knew when I came in, signing the one-year deal," Eckstein said, "that if things didn't go well, this was a possibility. The one thing, though, we've got great guys coming in. Johnny Mac has been playing outstanding. I think we've seen the emergence of Joe Inglett and Scutaro.
"Being on the other end, watching those guys play, it's been a pleasure, because they go out and play the game the right way."
Eckstein's teammates said the same about him.
"He's been a great teammate," McDonald said. "You watched the way he prepared every day -- whether he was playing or he wasn't playing -- how much he gave, it didn't matter if he wasn't in the lineup."
In 62 games with Gaston at the helm, Eckstein has started just six games at shortstop, garnering playing time at second base and as the designated hitter as well. On Saturday, Eckstein started at short for the first time since July 26, and his appearance in the lineup as the DH on Sunday marked his first consecutive starts since Aug. 5-6.
Blue Jays general manager J.P. Ricciardi said the lack of playing time available for Eckstein was a driving force behind trying to trade him to a contending club this month.
"You kind of look at the player and say, 'Hey, let's try to do right by the player,'" Ricciardi said. "We tried to put him in a spot where, A, he's going to go to the playoffs and, B, he's going to get a chance to play, which is what he wants to do more than anything. He's just an absolutely great guy."
In 76 games for the Blue Jays this season, Eckstein hit .277 with one home run and 23 RBIs, posting a .354 on-base percentage. He joined the Jays after spending the past three seasons in the National League with the Cardinals, with whom he won the 2006 Most Valuable Player Award in the World Series for his part in St. Louis' run to the title.
Eckstein played for the Angels from 2001-04 and Los Angeles also engaged in recent talks with the Jays about possibly reacquiring the infielder. L.A. is currently without shortstop Maicer Izturies (left thumb) and second baseman Howie Kendrick (left hamstring), and Erick Aybar is day-to-day with a left leg issue as well.
The Angels also reportedly showed interest in Scutaro and McDonald, but the Jays were reluctant to part ways with either player -- both regular starters since Gaston's arrival. Talks with the Angels eventually broke down, paving the way for the deal with the Diamondbacks, who agreed to send the 23-year-old Beck to Toronto.
Toronto selected Beck during the 2004 First-Year Player Draft, but he didn't sign with the Jays at the time. The right-hander was later picked up by Arizona in the 14th round of the 2006 Draft, and this season, Beck has gone 8-5 with a 3.67 ERA in 32 games between stints with Class A South Bend and Class A Visalia.
"He's a kid with a big arm -- a good fastball," Ricciardi said. "We drafted him out of high school and we didn't get a chance to sign him then. Our scouts like him a lot and he's the guy they pushed for in the trade. We were able to get him."
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.