Nearly two years later, the 31-year-old will come full circle Saturday when he takes the mound for the D-backs to face his old team, a day after Haren lost to Arizona.
In his last start, also against an American League West team, Saunders allowed just one earned run in six innings in a 4-3 victory over the Athletics on Sunday.
"I made some good pitches," Saunders said after the game. "They are a scrappy team. Their numbers aren't the respect they get. Can't take them for granted."
Opposing Saunders for the Angels will be right-hander Ervin Santana. The 29-year-old hasn't seen much success in his last four outings.
In 20 1/3 combined innings, Santana has surrendered 23 earned runs to increase his ERA from 4.22 to 5.74.
Santana's most recent start was particularly poor, as he gave up seven earned runs on nine hits over 5 2/3 innings against Colorado. The Angels' offense bailed out its pitching, however, defeating the Rockies, 10-8.
"I know it's not going my way right now," Santana said after the game.
Saturday will be the righty's second career start against the D-backs. He earned a win in June 2006 at Chase Field by tossing six innings of seven-hit, two-run ball.
Angels: Weaver progressing
Ace Jered Weaver is one step closer to returning to the rotation after throwing a 60-pitch simulated game on Friday.
Weaver, who has been on the disabled list since May 29 with a lower back strain, threw his full repertoire of pitches in a four-inning, simulated outing and said he felt no pain or discomfort afterward.
Weaver will next throw a bullpen session on Sunday and then have a discussion with the team's medical staff about when Weaver can return to the rotation.
"We want to make sure we don't miss any steps, and he's where he needs to be," Angels manager Mike Scioscia said. "Obviously, the first look out of the workout he felt great. We'll see how he feels tomorrow, play a little catch, and then Sunday throw a bullpen and see how he feels. Then we can make a determination of exactly where he is."
In 11 starts this season before going to the DL, Weaver (6-1) had a 2.61 ERA with 57 strikeouts and 15 walks.
D-backs: Young recalls All-Star experience in Anaheim
Outfielder Chris Young thought about his experience in the 2010 All-Star Game when he first walked into Angel Stadium on Friday.
Young was selected to represent the D-backs in the All-Star Game that year in Anaheim. It was his first and only visit to the ballpark before Friday.
"It's a weird little feeling because I'm in the same clubhouse, the same batting cage, the same everything," Young said. "I've always just associated this locker room with the All-Star Game."
Young wound up catching the final out in that All-Star Game, the lone appearance he has made in the Midsummer Classic thus far.
"It was one of the best times of my life as far as my baseball career goes," Young said. "Going to the playoffs tops that by a lot, but from a personal level, that was right at the top."
Angels reliever Ernesto Frieri is the first Major League pitcher with 34 or more strikeouts and no earned runs allowed in his first 18 innings with a new club.
The Angels have won five of their last seven games against the D-backs, including a three-game sweep June 26-28, 2009, at Chase Field. In Anaheim, however, the D-backs hold the edge over the Angels with a 5-2 record.