The damage started with Jonathan Broxton, who entered in the seventh in relief of Michael Wacha. Broxton allowed a home run to the first batter he faced, Anthony Rendon, then gave up back-to-back singles. He struck out Chris Heisey for the first out but was pulled from the game in favor of Dean Kiekhefer. The lefty Kiekhefer walked Ben Revere to load the bases, then served up a back-breaking grand slam to pinch-hitter Jayson Werth.
"I was trying to go with a fastball in -- run him back over with a sinker and get a ground ball in that situation," Kiekhefer said after the game. "Unfortunately, I left it down the middle for him and he put a good swing on it."
Matheny was forced to rely on Kiekhefer in a one-run game because Kevin Siegrist and Seung Hwan Oh were unavailable, having both pitched frequently in the last week. If Matheny had his full complement of relievers available, he could have used Siegrist to match up against Revere and then brought in Oh to face the lefty-smashing Werth.
Still, Matheny said, the Cardinals need their less-used bullpen arms to come through in key situations as well.
"We can't just keep using the same guys every night. We're going to blow them out," Matheny said. "We needed a couple other guys to try and come through for us, and we couldn't hold them back."
The Cardinals' bullpen woes didn't end in the seventh. Tyler Lyons came in to pitch the eighth and promptly allowed a single to Rendon and a home run to Wilson Ramos. After a walk and a single, Lyons escaped the inning by inducing a double play and an inning-ending groundout.
St. Louis' bullpen has been solid this season, entering Sunday with a 3.58 ERA that ranked 12th in the Major Leagues and a 1.21 WHIP that ranked 10th. But Sunday, with Oh and Siegrist unavailable and several relievers -- most notably Kiekhefer -- forced from their usual roles, everything fell apart.
"We need guys to come in and get big outs in situations they haven't been in because we're kind of in a situation we haven't been in," Matheny said.
Alex Putterman is a reporter for MLB.com based in Washington. This story was not subject to the approval of Major League Baseball or its clubs.