While De La Rosa looks to continue his current scoreless stretch while trying for a third straight winning start, Bumgarner hopes to maintain his recent success versus Colorado and help the visiting Giants to an 11th consecutive victory over the Rockies on Friday night.
De La Rosa (4-3, 2.98 ERA) has not allowed a run in 14 straight innings, and has yielded just five hits in two starts since he gave up six runs and 11 hits in four innings of a 6-2 loss at Dodger Stadium on April 30.
He's also given up five hits over 12 scoreless innings to win both his starts at Coors Field this season.
The left-hander took a no-hitter in the seventh inning before he gave up two hits over those seven frames in Sunday's 8-2 win at St. Louis.
"He's dominated some good lineups in this league," manager Walt Weiss told the Rockies' official website. "When he's commanding his stuff, he's one of the tougher left-handers in the National League."
De La Rosa has a 6.32 ERA while losing three straight starts against the Giants (24-17) - all at San Francisco. He gave up a three-run homer to Hunter Pence in six innings of a 4-2 loss to the Giants on April 8.
He's 4-1 with a 3.49 ERA in six starts versus San Francisco at Coors Field.
Bumgarner (4-1, 2.18), meanwhile, is 6-0 with a 2.08 ERA in seven starts against the Rockies (21-20) since he went 0-3 with a 3.00 ERA in his first five. He gave up two runs and overcame five walks to last 5 2-3 innings in that victory opposite De La Rosa last month.
The left-hander bounced back after giving up five runs in six innings of a 6-2 loss at Philadelphia on May 6, yielding one and striking out a season-high 11 in seven of a 10-1 win over Atlanta on Saturday.
The Rockies should feel the same way after they blew a 6-0 lead in Thursday's 8-6 loss to San Francisco. Angel Pagan hit a tiebreaking two-run single in the sixth inning and Marco Scutaro added two hits to extend his hitting streak to 15 games for the Giants, who have won 35 of 45 over the Rockies, including 12 of 14 at Coors Field.
"We're awesome,'' San Francisco first baseman Brandon Belt said. "We got down early (Thursday), but there was a lot of game left. We don't give up.
The ex-Rockie Scutaro is batting .475 during his current hitting streak and .455 while hitting safely in 13 straight games versus Colorado.
Pagan has batted .371 with four RBIs in his last eight against the Rockies.
Catcher Wilin Rosario hit a three-run shot for one of the three homers Thursday for Colorado, which has dropped seven of nine.
"It was just a bad game," said Colorado outfielder Carlos Gonzalez, who is 4 for 42 (.095) in his last 13 games against the Giants.
Rosario is 6 for 13 with two home runs and six RBIs in his last three home games versus San Francisco.