De La Rosa will lead the Rockies into a three-game series in Arizona starting Tuesday, as Colorado looks to expand its 4 1/2 game lead in the NL West.
After the left-hander limited the Cubs to one earned run and struck out nine last week, manager Jim Tracy was most impressed with De La Rosa's ability to pitch with the lead.
"All of a sudden, it just seems to me there's a different gear that shows up," Tracy said. "That's the sign of a guy that's beginning to understand how to be a winning pitcher on a regular basis. That's what I saw tonight."
The Rockies have a Major League-best 10-3 record on the road this year.
Joe Saunders will need to straighten out his problems at Chase Field, where he's 0-2 with an 8.80 ERA in three starts this season. The 30-year-old left-hander has allowed at least five runs in each of his home starts.
"I pitched well here last year," Saunders said. "I like the park. I'd rather have the roof closed if possible -- I've heard some stories about that, but no excuses."
His last start lasted 5 2/3 innings, when he yielded six earned runs, including two homers, to the Phillies. But he struck out eight in the process, and felt like he had good stuff.
"I made some good pitches, so what are you going to do?" he said. "You've got to keep your head up, turn the page and go get them next time. I don't think I'm pitching that bad, it's just the results aren't there yet."
If Saunders can give his team a lead after the sixth inning, the Diamondbacks should be fine. They're 11-1 this season when leading after six innings.
J.J. Putz recorded his sixth save of the season on Sunday, and has yet to blow a save in his tenure as the Arizona closer ... Joe Paterson has thrown 11 straight scoreless outings, the fourth-longest streak by a D-backs pitcher to begin his career ... Ryan Roberts continued his torrid start with his sixth home run of the season Sunday. His career high is seven in 2009, when he had 305 at-bats ... The Rockies have more home runs against left-handed pitchers (12) than any other team in the NL this season.