PHOENIX — After 151 games, the Giants finally have a balanced team. But not in a good way.

They tried to contend all season with a lopsided roster, hoping they could squeeze out enough runs to support a world-class pitching staff.
Now the pitching is as bad as their offense, their bedrock rotation suddenly needs a retrofit and their playoff chances appear to be in complete disrepair. Matt Cain completed a stunningly rotten turn through the starting five, getting blasted for seven runs in 2 1/3 innings, as the Arizona Diamondbacks beat the Giants, 10-8, at Chase Field on Tuesday night.
Combined with Colorado’s victory, the Giants trail the Rockies by five games for the NL wild card with 11 to play. They’re tied with the Atlanta Braves now, too.
“None of us have done what we wanted to,” said Cain, whose outing was the shortest of his career not related to an injury. “We had a chance to win, and we let it go. It’s definitely disappointing. We’re a group of guys who push each other. I feel I let a lot of guys down.”
Cain appeared poised for a different outcome after he hit a two-run triple — the first of his career — to give the Giants a 3-0 lead in the second inning.
But he gave back three runs in the bottom of the second and didn’t survive the third, allowing seven hits over a span of 12 batters.
Cain flatly rejected the suggestion that his long sprint, combined with the time of year, might have burned all the vapors remaining in his tank. Manager Bruce Bochy wasn’t sure, saying, “It’s a hard one to answer. I will say he’s in as good a shape as anyone on the staff. He’s carried a pretty good workload this year. It’s going to happen.”
Only the St. Louis Cardinals have logged more innings from their starting pitchers this season, and perhaps it’s starting to exact a toll.
In their past five games, Giants starters have a 13.26 ERA and have retired two batters beyond the fourth inning.
Cain (13-7) might have knocked himself off a few Cy Young Award ballots as his ERA soared from 2.71 to 2.99.
“I can’t leave him out there to get beat up too bad,” Bochy said. “He’s been too good for us and we have to protect those guys.”
Bochy couldn’t have liked what he saw from catcher Bengie Molina either. For the second time in three games, Molina didn’t bother to make a mound visit to settle down a pitcher in trouble.
Bochy took out Molina as part of a double switch when he went to pull Cain.
“I just felt that was the move to make,” Bochy said.
Tied for the wild card as recently as Aug. 31, the Giants are 9-11 in September and in danger of their first losing month of the season.
With the bullpen stretched again, Randy Johnson had an opportunity to make what might have been his final appearance at Chase Field. The 46-year-old left-hander received polite applause upon his introduction in the seventh inning, and he showed a little of his old heat while striking out the side. But he also gave up a solo home run to second baseman Rusty Ryal.
Cain didn’t induce many swings and misses. The Giants regained the lead in the third when Andres Torres tripled and scored on Pablo Sandoval’s single, but Cain retired only one of the five batters he faced in the bottom of the inning.
That was Mark Reynolds, who struck out for the 204th time to tie his own year-old major league record for a season. Rookie Madison Bumgarner struck out Reynolds in the fourth as Arizona’s third baseman established a new standard for prodigious whiffing.
Cain didn’t give up a home run, but only because instant replay was utilized to overrule Gerardo Parra’s drive that hit below the yellow line in right-center field.
“The last couple games, it’s been a pitch here or there,” Cain said. “Today it was a lot of ’em. There wasn’t a whole lot of good that came out of the way I threw the ball. I kept making mistakes over and over.”