Bud Black wasted no time using two pitchers recalled on Monday, but it didn’t bode well for the Colorado Rockies. Jairo Diaz, making his first MLB appearance since undergoing Tommy John surgery last year, and Chad Qualls, fresh off the 10-day DL were both called to the mound in a 9-2 loss to the San Francisco Giants, as once again Colorado’s starting pitching could not hold up. The Rockies, losers of six straight, even had to trot out starter Antonio Senzatela for two innings in relief of German Marquez in the loss.

Marquez (5-4, 4.38 ERA), lasted just four innings at AT&T Park, allowing five runs on seven hits. Senzatela looked strong in two innings of relief, striking out two and allowing just one walk. Qualls did not fare well in his return, surrendering two hits and a run in 0.1 innings. Mike Dunn allowed one hit to close out the seventh inning for Qualls. It was a rocky return for Diaz in his one inning of relief. He gave up three runs (two earned) on four hits. Ian Desmond committed an error in left field to start the inning.

Jeff Samardzija (3-9, 4.63) had lost his previous three starts against Colorado this year, but limited Colorado to two runs over 6.1 innings, scattering six hits. Hunter Strickland, Sam Dyson and Kyle Crick combined to keep the Rockies off the board following Samardzija’s departure.

The top of the order did the most damage for San Francisco. The Giants’ first four hitters combined for 10 hits on the night. Buster Posey led the way with three hits and three RBIs. Hunter Pence was 3-for-5 with a pair of runs scored. San Francisco was 7-for-15 in the game with runners in scoring position. Colorado was just 2-for-7.

The loss extends Colorado’s longest losing streak of the season to six games, all against the National League West. The Rockies remain 4.5 games out of first place after the Angels beat the Dodgers, and three games behind Arizona for the top Wild Card spot.

Colorado and San Francisco continue their three-game series on Tuesday. Jeff Hoffman (4-1, 4.29 ERA) will try to rebound from his first loss of the season for Colorado. Matt Cain (3-7, 5.54 ERA) goes for the Giants. First pitch is scheduled for 8:15 p.m. MDT.