CHICAGO _ With a series against the Cubs hanging in the balance, Giants manager Bruce Bochy declared he needed a quality start from pitcher Ty Blach and second baseman Pablo Sandoval.
But less than halfway through the Giants' 8-3 loss, Blach and Sandoval walked off the field together as Bochy double switched his starting pitcher and switch-hitting infielder out of the game.
With his top two second basemen on the disabled list, Bochy inserted Sandoval into the starting lineup at the position for the first time in his major league career. The experiment lasted just four innings, as Sandoval was yanked after grounding into a 6-4-3 double play while Blach was pulled after his worst outing of the year.
Blach has failed to record more than 13 outs in four consecutive starts and on Sunday, he suffered with erratic command that led to seven Cubs hits and four walks.
The left-hander is battling for the right to remain in a rotation that could soon feature Madison Bumgarner, as Bochy indicated the team will consider asking its ace to pitch Friday at AT&T Park after making just a single rehab start.
With the final three games of their road trip set for the hitter-friendly confines of Coors Field, Bochy let Blach work through three stressful innings before pulling him in favor of reliever Pierce Johnson in the fourth.
By falling three games below .500, the Giants are three back of the first-place Rockies heading into the final series of their road trip and only a half game ahead of the fourth-place Dodgers.
After the Giants capitalized on an RBI infield single from Sandoval and a two-run, two-out hit from left fielder Mac Williamson to take a 3-0 lead in the first, Blach surrendered three first inning runs and allowed the Cubs to tie the score.
The first two balls hit in the bottom of the first found Sandoval's glove, as he nearly threw out Albert Almora, Jr. on a leadoff single that nicked off Blach's glove and rolled toward second. Sandoval spent the past month taking grounders at second base to prepare for Sunday's opportunity, and showcased impressive range with a diving stab to take away a hit from Javier Baez on the next ball in play.
Though Sandoval's presence in the order netted the Giants a two-out rally in the first, he was forced to hit from the right side of the plate against reliever Randy Rosario in the fourth. With two runners on and one out, Sandoval hit a chopper to shortstop that turned into an inning-ending double play.
After Blach walked Rosario in his first career plate appearance and allowed a long double to Almora, Jr., Bochy walked to the mound and removed both players he needed quality nights from.
When former Cubs pitcher Pierce Johnson replaced Blach, Baez greeted him with a go-ahead three-run home run to spoil his homecoming.
While the Giants have struggled to score on their current road trip, they wasted a slew of early chances including a bases loaded, no out situation in the top of the third. After Blach, Gorkys Hernandez and Andrew McCutchen reached to kick off the inning, Brandon Belt and Evan Longoria struck out and Brandon Crawford lined out to end the threat.
The Giants loaded the bases again in the third, but a McCutchen groundout helped Tyler Chatwood escape the inning.
San Francisco's inability to make Chatwood pay for his inconsistent command played a pivotal role in Sunday's outcome, as Cubs manager Joe Maddon needed to remove his starter in the top of the third.
Chatwood barely threw more strikes, 46, than balls, 42, and issued five walks in a performance that drew loud jeers from his home crowd. However, Chicago's relievers proved far more effective, keeping the Giants off the board the rest of the night after Chatwood exited.
