(Sports Network) - Right-hander Edinson Volquez can get back to .500 for the first time since late July when the San Diego Padres visit the Arizona Diamondbacks in the finale of a three-game series at Chase Field.
Volquez, in his first season with the Padres after four with Cincinnati, was 2-2 in mid-May before dropping four straight decisions. He climbed back to 7-7 after beating the Reds on July 30, but fell back to 7-9 before a 3-1 decision over Pittsburgh in his last start Aug. 20.
In that game, the Dominican allowed a run on five hits - with 10 strikeouts - in 6 2/3 innings.
He picked up 17 of his 41 career major-league wins in his first season with Cincinnati in 2008, after he was acquired from Texas for Josh Hamilton.
In five starts against Arizona, he's 0-1 with a 4.15 earned run average.
The Diamondbacks had pegged Joe Saunders to start Sunday's finale, but the left-hander was dealt to the Baltimore Orioles earlier in the day for reliever Matt Lindstrom.
Instead, Arizona will rely on righty Trevor Cahill, who is winless in his last four starts and 9-10 on the year with a 3.86 ERA. Cahill did not get a decision on Tuesday against Miami, as he surrendered four runs and seven hits in 5 1/3 innings.
He is 1-1 in three starts against the Padres with a 1.29 ERA.
On Saturday, Clayton Richard pitched eight innings and San Diego matched a season-high with its sixth straight win, 9-3. Chase Headley, Carlos Quentin and Yonder Alonso homered off Ian Kennedy, as the Padres won their sixth in a row at Chase Field.
Richard (11-12) gave up seven hits and three runs, including a pair of homers. The lefty has won four of his last five starts, and has pitched at least eight innings in three of those games. He's 5-0 in seven career games against the Diamondbacks.
Justin Upton, who celebrated his 25th birthday, hit a two-run inside-the-park homer for Arizona. Aaron Hill also went deep for the Diamondbacks, who will try to avoid the three-game sweep Sunday.
Kennedy (11-11) allowed four hits and six runs over 5 1/3 innings to lose for the first time in seven career decisions against the Padres.
San Diego won five of the initial nine games between the teams in 2012, including a three-game sweep in Phoenix from July 2-4. Arizona won the series last year, 11-7.