PITTSBURGH -- When the rain started to fall in the third inning of the Pirates’ matinee against the Cardinals, manager Derek Shelton’s original game plan went straight into the trash. For the third time this week, the bullpen came to the rescue.

When Shelton pulled starter Luis Ortiz after just two-plus innings due to the rain delay, seven relievers -- Angel Perdomo, Yerry De Los Santos, Jose Hernandez, Dauri Moreta, Colin Holderman, Yohan Ramirez and David Bednar -- combined to cover seven innings as the Pirates beat the Cardinals, 4-3, on Saturday at PNC Park. The game plan may have been frantically rewritten on the fly, but the relievers pulled off quite the improv job.

“You run through the script of a game and all of a sudden you lose your starter after two,” Shelton said. “You have to just try to pick the matchups, and I think we did a really good job with that today."

It’s been a busy week for the bullpen, which has, more or less, been responsible for three of the last four wins.

On Tuesday, Moreta, Hernandez, Holderman and Bednar combined to pitch 4 2/3 scoreless innings as the Pirates beat the Giants. On Friday, Rob Zastryzny, Cody Bolton, Ramirez, Holderman and Bednar collectively covered five innings in an emphatic comeback victory against the Cardinals. This afternoon, however, was the most collective effort of the three as Shelton used every reliever in his bullpen except Zastryzny.

Ortiz had just thrown his 32nd pitch of the afternoon -- a ball that ran the count against Tommy Edman to 2-0 -- when the game came to a halt. Despite the temperature at first pitch being 91 degrees with a sunny sky, it opened up and the rain began to pour with such ferocity that the game had to be delayed. The crowd collectively booed and groaned as PNC Park’s grounds crew jogged onto the field and placed the tarp over the diamond.

If the delay was short enough, the Pirates planned to allow Ortiz the opportunity to continue pitching. When the delay dragged on, lasting approximately an hour, Shelton opted to emphasize safety and pull the plug on Ortiz’s afternoon. The right-hander’s final line: two-plus innings, one run allowed via a home run, two walks and one strikeout.

"If we're going to err there, we're going to err on the side of caution,” Shelton said. “Make sure that he's OK and doesn't get hurt.”

With Ortiz’s afternoon over, the bullpen was tasked with completing seven innings. At the beginning of the season, Shelton could have rolled with either Wil Crowe or Chase De Jong, a pair of former starters, to eat the bulk of the innings and save the bullpen. With Crowe on the injured list and De Jong having been designated for assignment, Shelton had to make do with his options.

Luckily for Shelton, he had a pair of fresh arms to utilize in Perdomo and De Los Santos, both of whom were added to the active roster from Triple-A Indianapolis prior to the game. Perdomo, a former starter, set the tone for how the afternoon would unfold with the best outing of his Major League career, retiring all seven batters that he faced and striking out three.

“I don’t even remember how many people he struck out,” said third baseman Ke’Bryan Hayes, who homered in back-to-back games for the first time in his career. “It seemed like he struck out everyone.”

From there, Shelton mixed and matched. De Los Santos recorded the final two outs of the fifth inning in his season debut. Hernandez faced three batters and got one out before handing the baton to Moreta, who pitched 1 2/3 scoreless innings, adding another demonstration of swagger to his collection.

Holderman, who began the eighth inning, was the only reliever this afternoon to get roughed up, allowing a two-run home run to Nolan Gorman that nearly cleared the right-field bleachers. The right-hander recorded just one out before being pulled for Ramirez, who got the inning’s final two outs and served as the bridge to Bednar.

Despite allowing a single to Jordan Walker, Bednar pitched a scoreless ninth to secure the win, recording his 12th save of the year and giving the Pirates a series victory over the Cardinals.

“The bullpen was outstanding,” Shelton said. “I don’t think you can say enough about our bullpen. [We lost] the starter because of the rain delay, and they just continued to push through.”