Originally scheduled to start Friday, Kershaw (14-3, 1.86 ERA) was moved up to give Greinke (elbow) extra rest. The two-time NL Cy Young Award winner threw a shortened bullpen session Tuesday and will be pitching on regular rest thanks to Monday's day off.
Kershaw is looking to bounce back after suffering a rare loss Saturday against Milwaukee. The left-hander, who had posted a 1.16 ERA in winning his previous 11 decisions, threw a five-hitter - but allowed two home runs for the first time this season - and struck out 11 in the 3-2 defeat.
"He's the best pitcher in baseball and he's been on a historically great run. It's incredible," Brewers slugger Ryan Braun told MLB's official website. "It's kind of fun to watch from afar. It's obviously extremely difficult to beat him. It hasn't happened much this year."
Leading the majors with six complete games, Kershaw is looking to win a third consecutive start versus the Padres. He struck out 11 in a three-hitter in a 2-1 victory July 10, improving to 10-6 lifetime against them.
The NL West-leading Dodgers (71-57) have dropped five of seven after falling 4-1 on Wednesday, and their lead over San Francisco has been reduced to three games. Scott Van Slyke had two of Los Angeles' six hits as the team went 0 for 5 with runners in scoring position.
Eric Stults threw five strong innings for San Diego (58-66), which improved to 11-6 this month. The Padres haven't posted a winning record in any full month since going 16-11 last September.
Tyson Ross (11-11, 2.70) had allowed two earned runs or fewer in 10 consecutive starts before Friday's 4-2 loss at St. Louis. The right-hander yielded three runs and four walks over six innings, dropping to 2-4 with a 3.44 ERA in his last six road outings.
"Plain and simple, I just didn't have fastball command the first inning," Ross said after walking the first three batters he faced. "It's hard when you shoot yourself in the foot like that."
Ross has never beaten the Dodgers, going 0-3 in his last four starts despite a 2.63 ERA. He's struck out 31 over 24 innings during those showings while receiving a combined two runs of support.
Ross has had a rough time with Carl Crawford, who is 6 for 10 with two doubles in their matchups. Crawford, 16 for his last 33, figures to be back in the starting lineup after grounding into a fielder's choice as a pinch hitter Wednesday.
Padres outfielder Cameron Maybin entered Wednesday's game as a defensive replacement in his return from a 25-game suspension for testing positive for an amphetamine. Maybin is hitting .247 with one homer in 63 games.
"When Cam is right, he's a good player," manager Bud Black said. "We've got to get Cam back to where he's a big contributor. His numbers were down a little bit before (the suspension)."
Maybin is 4 for his last 36 against the Dodgers and 2 for 18 versus Kershaw.