PITTSBURGH • The Cardinals awoke Saturday believing A.J. Burnett would be making his fourth rehab start less than three hours away in Altoona, Pa.

Because Burnett instead arrived unannounced at PNC Park Saturday afternoon, the Cardinals found their prolific offense rocked to sleep.

On a damp, raw night when starting pitcher Jake Westbrook offered the Cardinals a quality start and 113 pitches, his offense failed to exploit three potential game-changing opportunities, including two against a bullpen that teetered in each of the final two innings.

The Pirates and Burnett made off with a 2-0 win before an announced crowd of 25,218. The Cardinals were left behind to account for a missed opportunity that left their Nos. 3-5 bats 0-for-10 with seven strikeouts.

"We had opportunities to do something and couldn't get it done," manager Mike Matheny said.

Sidelined by a fractured orbital bone suffered in a spring training bunting miscue, Burnett tempted the Cardinals with a golden first-inning chance only to swap it out with seven dominant innings. After two walks sandwiched around a hit loaded the bases with none out, Burnett escaped unscathed with two strikeouts and shortstop Clint Barmes' leaping snare of catcher Yadier Molina's two-out line drive.

Burnett entered the fifth inning having retired the last 12 hitters he had faced. After the first-inning threat the Cardinals never pushed a runner past first base against him.

Ten days after the Cardinals' Class A Palm Beach club routed Burnett for eight runs (five earned) in less than two innings, the parent club suffered its second shutout loss this season.

Kevin Correia was listed as the Pirates' starter until midafternoon. The Cardinals didn't use the Pirates' pitching bait-and-switch as an excuse, but even those who had previously faced Burnett were caught off guard by his effective slider and ability to mix locations and speeds.

"He did a good job. He made pitches. We had our chance early and didn't do anything with it," said right fielder Carlos Beltran, who struck out three times.

"He pitched a good game. He pitched better than us," said Molina, the only hitter who faced Burnett in his last appearance against the Cardinals in 2005. "I thought he was going to use his fastball more. But he mixed it with a breaking ball, and his breaking ball was good."

The Cardinals squandered opportunities in the last two innings against a vulnerable bullpen. Consecutive singles by center fielder Shane Robinson and replacement second baseman Tyler Greene to lead off the eighth inning against Juan Cruz were followed by a sacrifice bunt from Rafael

Furcal. The inning's first out put the tying run in scoring position with one out but left Matt Carpenter to face lefthanded reliever Tony Watson and slumping left fielder Matt Holliday to deal with righthander Jason Grilli.

"I'd do that again tomorrow," Matheny said about a move that aimed for a tie game. Carpenter suffered his fifth strikeout in nine at-bats this season against a lefthander. Holliday struck out for Saturday's third time, and dropped into a 3-for-21 skid.

Pirates closer Joel Hanrahan created his own problems with back-to-back one-out walks in the ninth. Facing a diminished bench, he struck out rookie pinch-hitter Erik Komatsu before Robinson grounded out to end the game.

The Cardinals finished 0-for-seven with runners in scoring position one night after going one-for-11 in the same situation within a 4-1 win. Hitting .287 overall, the Cardinals are at a more mortal .249 (with eight home runs) with runners in scoring position.

The hitting brownout deprived Westbrook of a third consecutive win on a night when his ERA rose to 1.31. The Pirates scored a fourth-inning run on a single through Westbrook's legs and two infield hits. They pushed the lead to 2-0 when third baseman Pedro Alvarez produced his second RBI single to score center fielder Andrew McCutchen, who led off the inning with a double that barely missed clearing the right-center field fence.

Alvarez entered the game two-for-30 (.067) and doubled both his hit and RBI totals.

"It was a ground ball, which is what I live and die by," said Westbrook, who entered with the league's highest ground-ball ratio. "Overall I felt like I was able to control the game, control the counts and give us a chance."

Burnett's unexpected arrival took it away.