Throughout their Summer Camp workouts, the Pirates warned that pitchers might be ahead of hitters at the start of this 60-game regular season. They only had three weeks to prepare at PNC Park, and only three exhibition games against another opponent, so it was going to be tough for hitters to feel like they were ready for the real thing.

Ready or not, the Bucs saw the real thing on Friday night. His name was Jack Flaherty.

“You watch him on video and think he’s good,” Pirates manager Derek Shelton said. “Then when you watch him live, you realize why he’s pitching Opening Day for them.”

The Cardinals’ right-handed ace held the Pirates to two runs in seven innings. The Bucs battled back twice, but Paul DeJong’s late two-run homer off Richard Rodríguez was too much to overcome. In the end, Shelton’s long-awaited managerial debut for Pittsburgh ended as a 5-4 loss at Busch Stadium.

• Box score

Here are four takeaways from the Pirates’ Opening Day defeat.

1. Joe Musgrove remains one of their best athletes.
Musgrove admitted that the timing of his delivery wasn’t perfect in his first career Opening Day start, and that may have led to a drop in velocity. His four-seam fastball clocked in at an average of 91.9 mph, -- down from 94.5 -- after he shortened his arm action last September.

But of the 99 pitches Musgrove threw, only two really hurt: a hanging curveball that Tyler O’Neill hit into Pittsburgh’s bullpen in the third inning, and a fifth-inning fastball that Dexter Fowler pulled to right for a homer.

“The two pitches that I left right over the heart of the plate were the two they did damage on,” Musgrove said. “But other than that, I felt I executed pretty well, especially when we needed a big pitch."

And when the Pirates needed a big play, Musgrove delivered. In the fifth, Kolten Wong cracked a line drive to center field and tried for third base. When Adam Frazier’s relay throw bounced off Wong and past third baseman Colin Moran, Wong tried to scamper home, but Musgrove showed why pitchers are supposed to back up bases.

Musgrove displayed his athleticism by sliding to retrieve the ball in foul territory, before flinging it toward the plate from his side. Catcher Jacob Stallings made a fine hustle play of his own, diving in front of Wong to tag him out and end the inning.

“I didn’t necessarily see where the plate was, but I knew the angle that I needed to be at,” Musgrove said. “As I threw the ball, I saw that I had more time than I thought and kind of wished that I had set my feet a little more. Throw got there in the air in enough time for Stalls to make a play and get a tag on him.”

2. They still have a lot of questions to answer in the bullpen.
The Pirates broke camp without closer Keone Kela (positive COVID-19 test), and they’ll be without right-hander Edgar Santana (suspension) all year. So, they need someone to step up in late-inning situations like the one Rodríguez entered in the eighth.

Rodríguez immediately gave up an infield single to Paul Goldschmidt before DeJong blasted a 90.5-mph fastball out to left-center field for a homer. It stalled the momentum Pittsburgh had established by pulling within a run in the seventh, and it was all too reminiscent of the early struggles Rodríguez endured last season.

The low velocity readings were also initially concerning, but Rodríguez's fastball bounced back to 92-93 mph as he retired the Cardinals’ next three hitters.

“I think the pitch that was hit out was at 90, and we would have preferred it was at 92. But after that, he settled down and executed some pitches, which is a good thing,” Shelton said. “I was proud of how Richie bounced back.”

3. Clay Holmes might be one of the answers.
Holmes relieved Musgrove with two outs in the sixth and immediately gave up an RBI single to Yadier Molina, but what he showed in the seventh was promising for a bullpen in need of big arms.

Holmes allowed only an infield single in a 17-pitch seventh, and his curveball looked like a legitimate weapon. He threw four curves in his at-bat against Tommy Edman: one called strike, one ball in the dirt and two that made Edman whiff.

“He gave us a chance to win the game, and that’s really all you’re asking for,” Shelton said. “Anything for this year is all based on what we’ve seen this year, and the strides that Clay has made have been tremendous.”

4. They will battle, but they need more power.
Pittsburgh’s lineup is probably deeper than expected, especially if Stallings can deliver the occasional hit like his two-run single off Flaherty in the seventh. The Bucs made it interesting in the ninth, too, as José Osuna singled in two runs against Cards closer Kwang Hyun Kim. Shelton mentioned several times how proud he was of their effort.

But in either of those situations, a drive into the gap or a blast over the fence would have turned the tide of the game. This lineup seems to be dependent upon Josh Bell and, eventually, Gregory Polanco to provide that kind of power. While the Pirates had to scratch and claw through single-filled rallies, the Cardinals changed the game with three swings.

“We were in the ballgame the whole night. They took the lead; we came back. They tacked on some more; we tacked on some more,” center fielder Jarrod Dyson said. “At the end of the day, we were one swing away from winning that ballgame or tying the ballgame. I felt like, for Game 1, we showed great signs. We can always look back and improve on that, what we did wrong and how we could have executed and things like that.”