HOUSTON — You'd think the Giants would be used to it by now.

A solid pitching performance wasted. A lesser opponent shutting them down. The feedback loop continued last night in a 3-1 loss to the Houston Astros at supposedly hitter-friendly Minute Maid Park.

But instead of resignation, there was frustration.

At getting manhandled by Brandon Backe, a pitcher who allowed 11 earned runs in his previous start. At blowing Jonathan Sanchez's first good outing in more than a month. At losing a game on three singles, including a broken-bat bleeder and a bunt hit that was intended as a sacrifice.

Now the Giants are mulling changes. A swap of slumping first baseman John Bowker and his sizzling Triple-A Fresno counterpart, Travis Ishikawa, is being discussed.

But catcher Bengie Molina, the team's unofficial conscience, said roster moves would not address a problem that has lasted all season and run too deep.

"I don't want to start anything, man, but it's pretty frustrating when we don't score runs," Molina said. "This is a team sport and I'm not blaming anybody or pointing fingers. I want to make that clear. But as a group, we're not scoring runs and we lose. That's it."

Molina waved off any talk of Manager Bruce Bochy changing the lineup or General Manager Brian Sabean bringing up fresh blood.

"It's up to us," he said. "Bochy can move the lineup all around, whatever he needs to do. But it's about doing it. You can get anybody from the stands, put a uniform on them and let them try. But in the big leagues, it's not about trying. It's about doing it, myself included."

The Giants couldn't get it done against Backe, a pitcher who entered with a 5.35 ERA and turned the pitching mound into a blast crater in his previous start.

As a result, Sanchez lost on a night that he took a no-hitter into the sixth inning. Backup catcher Humberto Quintero spoiled the bid with a broken-bat blooper that fell just beyond shortstop Ivan Ochoa's glove. Backe was credited with a single after Sanchez misplayed his sacrifice attempt.

Ty Wigginton stung a two-run single to center field to put the Astros ahead, then added a solo home run off Billy Sadler in the eighth.

At least it was an encouraging seven innings for Sanchez, who appeared to be hitting a wall as passed his professional high for innings in a season. Over his previous six starts, he had retired just one hitter beyond the fifth inning.

"He hit a rut," Bochy said. "But that's part of this game for young kids, dealing with tough times."

At what point is it no longer productive to let a young player take his lumps? That's what the Giants are weighing with Bowker, who is batting .156 since the All-Star Break.

"I'm not keeping it simple," Bowker said. "I'm thinking too much."

Meanwhile, Ishikawa just completed a scorching run in which he hit seven home runs in 33 at-bats. Since being promoted from Double-A in July, he was hitting .317 with 16 homers in 167 at-bats.

With the outfield already crowded, the Giants couldn't just promote Ishikawa and hope to get Bowker consistent at-bats.

Ishikawa was once on the verge of flaming out as a prospect and there were times the Giants questioned his commitment. But farm director Fred Stanley said the organization didn't light a fire under him.

"He did it himself," Stanley said. "Some people take a little longer maturity wise. He's driving the same pitches that he fouled off last year. He looked like he waited a long time just to see if the pitch was a strike. Now he's confident enough to know he can expand the zone, attack pitches and drive them out of the ballpark."

All qualities currently lacking on the Giants' roster.