Reaching the postseason is largely out of their control, but the Arizona Diamondbacks have a good chance to move above .500 for the first time in nearly a month with a sweep of their pesky division rival.
Arizona has won eight of 12, but is still 4 1/2 games behind St. Louis for the second NL wild card with four other teams also in the mix.
The chances of the defending NL West champs jumping over those clubs may be slim, but the Diamondbacks (74-74) are trying to do their part while looking to win four straight for the first time since Aug. 16-19.
Arizona, which last had a winning record Aug. 25, won 6-2 Wednesday. Adam Eaton tripled to spark a three-run fifth inning and starter Trevor Cahill went six innings.
''We were seeing good pitches and not missing,'' Justin Upton, who had a pair of doubles and scored twice, said. ''That's how the offense gets going.''
The Diamondbacks have won their last two home games against the Padres after losing the first six. They were outscored 42-20 in those losses, but have allowed four runs in this series.
They'll try to complete the sweep Thursday, but have to face Richard (13-12, 3.74 ERA).
Richard is 5-0 with a 3.80 ERA in seven career starts against Arizona, including 2-0 with a 2.31 ERA in three starts this year. He's pitched at least eight innings in the last two meetings.
The left-hander is trying to win his fifth consecutive decision overall. He has a 2.91 ERA over his last five starts and gave up two runs and three hits over seven innings of a 3-2 win against the Cardinals on Sept. 12.
The Padres (71-78) have won Richard's last five starts as they try to avoid losing three straight after coming into the series having won 19 of 25. They are 3 for 14 with runners in scoring position in this series.
Chase Headley, who is 2 for 6 in the first two games, and his teammates had better success against Diamondbacks scheduled starter Tyler Skaggs (1-2, 5.55 ERA).
Skaggs allowed five runs and gave up a three-run homer to Headley over three innings of a 6-5 loss to San Diego on Sept. 7.
The left-hander, who won his major league debut Aug. 22 against Miami, also struggled his last time out. He gave up five runs and five hits over four innings of a 6-2 loss to San Francisco last Friday.
"It's been unacceptable on my part the last two outings,'' Skaggs said. ''It's almost been embarrassing. As a young pitcher you have to learn to get out of jams like that. I was fortunate my first two outings to get out of jams.''