Seymour's short start costs Giants a chance to gain in Wild Card race

SAN FRANCISCO -- The Giants have three established starters leading their pitching staff in Logan Webb, Robbie Ray and Justin Verlander, but the back end of the rotation is far greener.

With Landen Roupp (left knee bone bruise) on the injured list, Kyle Harrison in Boston and Hayden Birdsong down at Triple-A Sacramento, the Giants have been leaning on a pair of rookies -- Carson Seymour and Kai-Wei Teng -- to make big starts in September.

But that inexperience has yielded mixed results, as evidenced by Seymour’s rough start in the Giants’ 5-3 loss to the D-backs on Wednesday afternoon at Oracle Park.

Seymour recorded only four outs in his third career start for San Francisco, surrendering four runs on six hits, including a leadoff home run to Geraldo Perdomo in the first inning.

Perdomo blasted an 0-2 sinker from Seymour out to right field to open the scoring and collect his first career leadoff homer, giving Arizona an early lead it wouldn’t relinquish. The D-backs continued to test Seymour in the second, stringing together three consecutive singles to kick off a three-run rally that knocked the 26-year-old right-hander out of the game after he threw only 38 pitches.

“I feel like I was throwing the ball well,” Seymour said. “The problem was getting ahead of hitters, and then they were just kind of hitting it where they weren’t. Pretty unfortunate. I just kind of feel like as a starter, you have to set the tone and I didn’t do that to the best of my ability today. It’s definitely a bummer, but I’ve got to move on from it, figure it out and just keep grinding.”

Four relievers -- Spencer Bivens, Keaton Winn, JT Brubaker and José Buttó -- combined to hold the D-backs to one run over the remaining 7 2/3 innings, but the Giants couldn’t dig out of the hole left by Seymour, who fell to 1-3 with a 5.23 ERA over 13 appearances this year.

“It looked like a game that could get out of hand early,” manager Bob Melvin said. “The bullpen came in and did a good job. They just put some pressure on [Seymour] early, and he didn’t have anything to really answer with.”

The Giants entered Wednesday with an MLB-high .891 OPS over their previous 16 games, but their bats went cold against D-backs left-hander Eduardo Rodriguez, who struck out six while spinning 6 1/3 scoreless innings. San Francisco didn’t get on the board until the eighth, when Rafael Devers smoked a 418-foot, 110-mph drive that hit off the top of the bricks in right-center field and fell for a two-run double. (Devers’ extra-base hit, unsurprisingly, would have been a home run in every other Major League ballpark.)

“When he hit it, I thought it was going in the bay,” Melvin said. “But that’s a pretty tough spot for him to hit it out, even in the daytime. It gave us a little momentum. We felt pretty good where we were. We couldn’t push them across. But after we got their starter out of the game, we put some pressure on them and had a chance.”

After falling short of a three-game sweep of the D-backs, the Giants are now two games behind the Mets for the third National League Wild Card spot, after the Mets lost, 11-3, to the Phillies on Wednesday evening. (The Mets hold the tiebreaker, so the deficit is effectively three games.)

The Giants, who are 13-4 over their last 17 games, will enjoy a respite on Thursday before kicking off a three-game series against the rival Dodgers on Friday night at Oracle Park. Verlander is scheduled to start the series opener, and the Giants are likely to use the off-day to skip Teng’s turn and have Webb and Ray pitch the final two games on regular rest.

That configuration should give the Giants their best shot against the Dodgers, though it’s clear that they’re going to need both Seymour and Teng to deliver more consistent production out of the back end of the rotation to keep their playoff hopes alive over the final half of September.

“There have been some good ones and some bad ones,” Melvin said when asked to assess the rookies’ performances. “It’s what we have right now. I think they’ve gained experience every time they go out there. The last time out for Carson was a really good one, and today wasn’t as good. I think it’s just trying to find a balance. If we have to cut them short, we’ll cut them short.”