On his way to Arizona, where he lives, is veteran southpaw Joe Saunders. The D-backs also acquired two young pitchers -- Rafael Rodriguez and southpaw Patrick Corbin -- along with a player to be named.
The deal with the D-backs was announced as the Angels were preparing to wrap up a four-game series with Texas at Rangers Ballpark, leaving Saunders -- and his now former teammates -- stunned.
Haren is signed through 2012 with an option for 2013. He is making $8.25 million this year and it escalates to $12.75 million each of the next two seasons. He can make $15.5 million in 2013 or be handed a $3.5 million buyout.
The Angels are hoping for the same kind of emotional lift from Haren, a man with ace talents, that the Rangers pulled from the acquisition of Lee from the Mariners on July 9.
"I would say he has that potential," Angels general manager Tony Reagins said when asked if Haren is on Lee's level as an elite starter. "Cliff is obviously a dominant pitcher. Dan Haren is a dominant pitcher.
"We're not expecting him to be the guy. We're expecting him to do what he does -- give us quality innings and help us accomplish our goal."
Haren, who started the 2007 All-Star Game for the American League in San Francisco when he was Oakland's ace, is 29 and in the midst of an un-Haren like season: 7-8 with a 4.60 ERA in 141 innings. He has 141 strikeouts against only 29 walks, but opponents are batting .285 against him.
Haren, a native of Monterey Park in Southern California, could start as early as Monday night against the Red Sox when the Angels return to Angel Stadium.
Angels manager Mike Scioscia said he needed to discuss it with the pitcher and "evaluate some things" before deciding when to slide his new right-hander into a rotation that features Jered Weaver, Ervin Santana and Joel Pineiro. Scott Kazmir is in the process of coming back from shoulder fatigue.
"I believe his turn would be tomorrow," Scioscia said of Haren. "We're going to get a chance to talk to him, see where he is. We've got guys on their regular turn."
Saunders is coming off one of his best efforts of the season, going seven innings and giving up a first-inning homer to Michael Young in a 1-0 loss to C.J. Wilson of the Rangers on Friday night. Saunders is 6-10 with a 4.62 ERA in 20 starts.
An AL All-Star in 2008, Saunders is 54-32 with a 4.29 career ERA in 115 starts.
"We really felt good about our starting five moving forward, but this is a huge opportunity for us to upgrade -- not only now but the next couple years," Scioscia said. "He's definitely a guy who's pitched in big games. He has his stuff and is a young veteran.
"It gives us a deeper front of the rotation. That's what every championship-caliber team strives to do."
Haren's best season was 2007, when he was 15-9 with a 3.07 ERA, but his 2009 was close. He was 14-10 with a 3.14 ERA, striking out a career-high 223 hitters in 229 1/3 innings.
For his career, Haren is 86-70 with a 3.71 ERA in 217 games, all but nine as a starter.
"It's a shock," said Saunders, who didn't see it coming as the Angels once again kept a tight lid on negotiations that had been ongoing. Reagins said it all came together quickly and that he's not done looking for ways to improve the club.
"I like the trade," Angels center fielder Torii Hunter said. "I also like Joe Saunders. But baseball doesn't operate that way; it's a business.
"It's a sad day in the clubhouse when you lose a family member. Joe's a guy I mess with every day, joke with every day. I feel he has nothing but upside. Obviously, the Diamondbacks love him. He's home. He gets to sleep in his own bed."
Hunter played with Haren in the 2007 All-Star Game and "got to know him a little bit. He's got some great stuff and good control. He's a cool guy, and he can deal."
The part about pitching at home -- he lives in Chandler, just outside Phoenix -- would appeal to Saunders, 29, later, when the shock had worn off. At the moment, he was wrestling with the notion of leaving the only organization he has known since he was taken in the first round of the 2002 First-Year Player Draft out of Virginia Tech, and it showed in his eyes.
"It's tough," he said. "I've loved playing with these guys. I guess it's time for a new start."
Rodriguez, 25, appeared in one game for the Angels this season, giving up a run in two innings. He was 0-1 with a 5.58 ERA last season in 18 games and 30 2/3 innings.
Corbin, 21, is a Syracuse, N.Y., native in his second year with the organization. He was a second-round pick in 2009 out of Chipola Junior College in Marianna, Fla.
Corbin is 8-0 with a 3.86 ERA in nine starts at low Class A Cedar Rapids. He has 42 strikeouts against 10 walks in 58 1/3 innings. He was 4-2 with a 5.05 ERA in 13 games for Orem in rookie ball last season.
Reagins said the D-backs have a list from which to select the fourth player in the deal and that they figure to make a decision soon.
"It comes together fairly quickly when there are fits and matches," Reagins said. "When there's a match, you work until you get it done."
The GM said he is doesn't have "limitations financially" as he pursues more deals with the July 31 non-waiver Deadline approaching.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.