"At this point, being on the West Coast has a lot of value to me, being near my family and going to a ballclub that is dedicated to winning," Haren said after Arizona's 10-inning loss to San Francisco. "I am really excited about going there and having a chance to win."
A three-time All-Star, Haren was one of the most prized pitchers available as the July 31 non-waiver trade deadline approaches, has averaged 15 wins over the past five seasons and was tied for the National League lead with 141 strikeouts. He also had allowed more hits (161) than any other pitcher in the NL.
Angels starters already lead the majors in innings pitched and have pitched six innings or more in 10 consecutive games. The Angels are tied for third in the AL with 56 quality starts.
"We really feel good about our starting five moving forward," Angels manager Mike Scioscia said. "This is a huge opportunity for us to upgrade not only now, but for the next couple of years. He's definitely a guy who has pitched in big games, has terrific stuff and he's a young veteran."
Saunders was stretching with his teammates before Sunday night's game against the first-place Texas Rangers when Scioscia pulled him off the field to meet in his office with general manager Tony Reagins. Later, Saunders, who lives in Arizona, choked up while speaking with reporters.
"I thought he was going to say, 'Hey, we need you to go on three days' rest,' but Tony was in the office and, you know, it's hard," said Saunders, who spent eight years with the Angels' organization. "It's part of the game. I totally understand. It's a business. It's just tough leaving the guys."
The Diamondbacks also receive reliever Rafael Rodriguez, who has been up and down with the Angels the past two seasons, and 21-year-old left-hander Patrick Corbin, a second-round pick in 2009, who was in Class A Rancho Cucamonga.
According to The Arizona Republic, the player to be named is Class A left-hander Tyler Skaggs, one of the Angels' top prospects.
With a starter and two solid prospects, the Diamondbacks found the right match for dealing Haren.
"[Saunders] brings an element to our club that I think we need," Arizona interim GM Jerry Dipoto said. "The prospects in the deal bring us talent that we need to build with. Therefore, I felt that this deal checked a lot of boxes for the Arizona Diamondbacks."
Given their precarious place in the standings, seven games behind Texas after Sunday's game, the Angels were hesitant to deal prospects for a
two-month rental. Haren is signed through 2012, but at a hefty salary. The Angels add just $1.8 million to this season's payroll, but they'll owe Haren $12.75 million next season and the same amount in 2012.
Haren is in the second season of a four-year, $44.75 million contract with a club option for a fifth year. He is due to make $12.75 million each of the next two seasons with a club option for $15.5 million in 2013. If the option is not picked up, Haren is due a $3.5 million buyout. His contract also includes a list of teams to whom he could veto any trade.
Haren, 29, is 7-8 with a 4.60 ERA. The Angels think the change of scenery to a contending team might help him regain his focus. Most reports indicated Haren likely was headed to the New York Yankees, though the Dodgers and other teams also had been involved in talks to acquire him.
Scioscia said Haren could start as soon as Monday night against the Boston Red Sox in Anaheim.
"I believe his turn would be tomorrow, but we're going to evaluate a couple of things and get a chance to talk to him and see where he is," the manager said. "We've got guys who are on regular turn now, so we do have the luxury of folding him in somewhere or putting him out there to pitch tomorrow."
Saunders, 29, is having a roller-coaster season. He's 6-10 with a 4.62 ERA in 20 starts. Saunders was an All-Star in 2008 and had a 54-32 record and 4.29 ERA in 115 games over six seasons with the Angels
"I've been in trade talks in the offseason and stuff like that but you never really think it's going to happen," said Saunders. "They obviously think highly of me, so it will be a new challenge."
The trade leaves the Angels without a left-handed starting pitcher until Scott Kazmir returns from the disabled list. Kazmir and Saunders have been the Angels' two most disappointing starting pitchers this season.
Reagins said he inquired about Haren weeks ago, but was told the Diamondbacks weren't going to move him until after this season. The Angels made inquiries on hitters like Adam Dunn, Prince Fielder, Jorge Cantu and Adam LaRoche, but wound up trading for versatile infielder Alberto Callaspo on Thursday and Haren three days later.
"I don't think we've said it had to be an impact bat," said Reagins, who added, "There are still opportunities out there. We're trying to improve our club. If we can find fits out there, we're going to still be aggressive trying to get them."
The Diamondbacks acquired Haren from the Athletics after Arizona finished with the NL's best record in 2007 and made a surprise run to the NL Championship Series.
Haren has been among the game's most durable pitchers with at least 33 starts and 216 innings each of the past five seasons. He was fifth in NL Cy Young Award voting last season.
"A top-of-the-rotation guy that's going to help us not just this year but years down the road," Reagins said. "The addition of Dan gives us five guys that are really talented."
Mark Saxon covers the Angels for ESPNLosAngeles.com. Information from The Associated Press contributed to this report.