For example: Pittsburgh's scheduled starter, left-hander Francisco Liriano, was scratched just moments before the game, leaving reliever Vance Worely to take over on short notice.
Then, the Pirates offense jumped on the Brewers early, scoring two runs on three pitches, and taking a 3-0 lead in the first inning only to watch that lead disappear on a trio of home runs.
"It was a crazy game," Pirates manager Clint Hurdle said. "Yesterday, I saw something I haven't seen in a long time -- a run scored on three pitches without a home run. I saw two runs scored on three pitches without a home run today."
Hurdle had to make a last-minute decision when Liriano, who reported to the ball park with tightness in his neck but tried to get through his usual pregame routine, just couldn't get comfortable.
Enter Worley, who had made seven starts for the Pirates this season, but none since May 14.
"If I was starting, usually I get out there a half hour early so I can get my long toss and everything in," Worley said. "As a reliever, we get out there early and throw during batting practice. I was already loose so I just got out there and got on the mound. I prepared myself the best I could for it."
He made quick work of the Brewers in the first but gave up back-to-back singles to open the second. Worley struck out shortstop Jean Segura and got catcher Martin Maldonado to bounce out, bringing up Brewers starter Jimmy Nelson, who ripped a two-run single up the middle to make it a 3-2 game.
Second baseman Scooter Gennett tied the game with an RBI single in the third and in the fourth, a 10-pitch walk to left fielder Gerardo Parra brought up first baseman Jonathan Lucroy, who ripped a hanging slider to left-center to give Milwaukee the lead.
"You never know, but I think the 10 pitches to Parra took some sting out of him," Hurdle said.
Worley got out of the inning without further damage and gave way to the bullpen, finishing his day with five runs -- four earned -- on seven hits and a walk and four strikeouts.
"You deal with a lot of adversity in this game," Worley said. "That just happened to be one of the ones I had to deal with that day. I just got loose as fast as I could, got as much as I needed as if I was coming in out of the pen and came in and tried to do as much as I could today."
Along with Lucroy's home run, solo shots by third baseman Aramis Ramirez and Khris Davis in the fifth and seventh innings, respectively, helped the Brewers' offense bail out Nelson after a rocky start.
Right fielder Gregory Polanco led off with a single that bounced off Lucroy's glove.
Neil Walker followed with a short blooper to center that Carlos Gomez couldn't handle, allowing a run to score, and a wild pitch to center fielder Andrew McCutchen allowed Walker to score, putting the Pirates up, 2-0.
McCutchen walked, left fielder Starling Marte singled and just when it looked like Nelson might catch a break, shortstop Jean Segura -- a late addition to the lineup after Pittsburgh scratched the lefty Liriano -- made a bad throw on what would have been a double play and McCutchen made it home to give Pittsburgh a 3-0 lead.
Nelson loaded the bases by hitting first baseman Pedro Alvarez with a 1-2 fastball but the Brewers finally got some good fortune when Marte was thrown out trying to score on catcher Francisco Cervelli's fly to right.
"That was huge," Nelson said. "A lot of times you don't see it, but that saves pitches, which helps us."
Nelson threw 24 pitches in the first inning but settled down after that and worked into the seventh inning before giving way to the bullpen. He was at 98 pitches at that point and finished with four runs on seven hits and three walks while striking out eight.
"I was really proud of the guys tonight," Counsell said. "I thought we didn't get off to a good start, but really the rest of the game, we played a good game the rest of the game. Jimmy was outstanding. We had some big defensive plays. Our offense every inning put pressure on them. We did a really good job with two outs. ... After the first three pitches, it was a pretty good game."
NOTES: Pirates LHP Francisco Liriano was slated to start Saturday but scratched just before first pitch with tightness in his neck. RHP Vance Worley started instead -- his first since May 14. Worley began the year in Pittsburgh's rotation and was 2-3 with a 4.38 ERA in seven starts. Since moving to the bullpen, he is 1-1 with a 1.80 ERA in 11 appearances. Liriano is the first member of the Pirates' opening day rotation to miss a start this season. ... Brewers manager Craig Counsell's original lineup was stacked with right-handers, but the Pirates' last-minute change allowed Counsell to put hot-hitting Gerardo Parra back in left field instead of Khris Davis. Scooter Gennett replaced Hernan Perez at second base. Counsell left Jonathan Lucroy at first, where he was making just his second start of the season.