While the Los Angeles Angels of Anaheim are finally starting to play to their potential, the team is still waiting for Ervin Santana to do the same. Tonight he tries to right the ship, as the Angels continue a three-game interleague set with the Arizona Diamondbacks at Angel Stadium.

Santana has won three of his last four decisions, but he hasn't pitched well at all. He beat Colorado on Sunday and allowed seven runs in 5 2/3 innings. Santana also surrendered seven runs in a loss to Seattle his previous time out and has given up 23 runs over his last four starts.

"I know it's not going my way right now," said Santana, who is 3-7 with a 5.74 ERA on the year.

Santana beat the D'Backs the only other time he faced them, allowing two runs and seven hits in six innings.

Arizona will counter with lefty Joe Saunders, who is 4-4 with a 3.48 ERA. Saunders defeated the Oakland Athletics on Sunday, holding them to just an earned run in six innings.

"I made some good pitches," Saunders said. "They are a scrappy team. Their numbers aren't the respect they get. Can't take them for granted."

This will be his first-ever appearance against the Angels, the team that made him their first pick back in 2002. Saunders pitched the first five-plus years of his career in Anaheim before being shipped to the desert as part of the Dan Haren deal.

Arizona got back to .500 on Friday, as Trevor Cahill pitched shutout ball into the eighth inning and the Diamondbacks knocked Haren around in his first start against his former team in a 5-0 victory. Aaron Hill blasted a three-run homer, while Jason Kubel had three of the 12 hits for the Diamondbacks, who won for the seventh time in nine games and improved to 32-32.

Cahill (5-5), who has given up just two runs over his last three starts - all wins - piled up a season-best eight strikeouts on Friday. The righty yielded three hits and a pair of walks, including one to Hank Conger before being lifted in favor of Brad Ziegler.

"I felt good tonight. I was able to mix it up and put guys away," Cahill said. "I had good defensive support. I had all four pitches working."

David Hernandez pitched the ninth to complete the three-hit whitewash.

Haren (4-7), who pitched for the Diamondbacks from 2008-10 and made two All- Star appearances before being traded to the Angels, was charged with eight hits and five runs over 6 1/3 frames. He had five strikeouts.

The Angels, who lost for the second time in seven contests, have a big mountain to climb if they're going to keep their interleague series success alive. They've won 11 of their last 12 interleague series spanning back to 2010. The Angels have not dropped an interleague series at home since June 14-16, 2010 vs. Milwaukee (1-2).

The Angels swept Arizona the last time these teams met back in 2009, but this is the Diamondbacks' first trip to Angel Stadium since 2001.