PHILADELPHIA -- A trademark of the A’s under longtime manager Bob Melvin was resiliency. No matter the situation, players never felt like they were out of the ballgame. 

Though a new leader is at the helm in first-year manager Mark Kotsay, that intangible quality was once again demonstrated by the A’s in Friday’s 9-5 loss to the Phillies at Citizens Bank Park.

An Oakland offense that was stagnant early against Phillies starter Aaron Nola, with only one hit through the first six innings, suddenly came to life in the seventh. Entering the frame trailing by five runs, the A’s knocked the right-hander out of the game and put themselves well within striking distance by stringing together a four-run inning, highlighted by Seth Brown’s booming three-run homer to right-center.

“Nola, last year he really performed. A lot of strikeouts,” Kotsay said. “To show that fight and get back in the game with a chance to at least tie or go ahead, that shows some good signs.”

That late rally is part of what Kotsay is seeking to carve out as his club’s identity: a gritty, grind-it-out group that pays no mind to opinions of third-party observers who project the A’s to take a major step back in 2022. The objective is to view this season as not a rebuild, but rather an opportunity for new players to establish themselves.

Of course, when a team finds itself in such a situation as the A’s do -- having traded away multiple stars and brought in several new faces -- growing pains are a part of the process. Here’s a look at what the season opener showed us about what ups and downs Oakland will likely face as it enters a new chapter:

Figuring out an inexperienced bullpen
It was evident during Spring Training that the bullpen was a work-in-progress with so many unproven arms vying for spots. That remains the case going into the regular season. Of the nine pitchers who make up Oakland’s relief corps, seven began the year with fewer than 25 Major League innings under their belt. Three of those inexperienced arms appeared in relief of Frankie Montas on Friday.

First up was right-hander Jake Lemoine, who entered in the sixth to make his Major League debut. Following Lemoine was fellow righty Domingo Acevedo and left-hander Kirby Snead, who together came in with a combined 18 2/3 innings pitched in the big leagues. The trio combined to allow four runs in the game’s final three innings, quickly zapping the momentum that had been gained from the offense.

“They’re down there trying to earn roles,” Kotsay said of the three pitchers. “Today, Lemoine came in a little excited and didn’t command the baseball as well as he needs to, but it’s his first outing. The guys that followed him, I think they’re all gonna just take time to get their feet on the ground.”

The lack of experience is not just limited to the bullpen. According to the Elias Sports Bureau, the 1,480 innings pitched by the A’s entire 14-man pitching staff marks the fourth-fewest innings entering a season by a team’s Opening Day roster since 1990.

Jelling a new defense together
For years, the A’s had a smooth operation on defense thanks to a strong unit led by Gold Glovers at the corner infield spots in Matt Chapman and Matt Olson. With both Matts now gone, the corner spots will feature multiple players rotating at each position. Regardless of who is out there, a sound defense will be key to winning games. On Friday, there were a few occasions where the gloves faltered.

The biggest instance came in the third inning when Tony Kemp appeared to make a tag on Bryce Harper at second base on a good throw from Cristian Pache in center field. However, a replay review determined that Kemp actually missed the tag, allowing Harper an RBI double instead of what would have been the second out of the inning. That inning eventually morphed into a laborious 32-pitch effort for Montas that saw the Phillies break the game open with three more runs.

“Anytime you have a call reversed, the momentum shifts,” Kotsay said. “Bryce did a great job of going in and sliding, keeping his foot down. I think Tony anticipated the foot coming up.”

The potential of 'Everyday Chad'
Mostly a utility player prior to this season, Chad Pinder is now in line for more of a regular role for the first time in his career. Batting cleanup on Friday, he helped spark the A’s offense twice, hammering a solo shot off Nola in the fourth for the team’s first hit of the game and later setting up Brown’s three-run blast with a single in the seventh.

There has always been intrigue over what type of production Pinder could give the A’s with a full season of everyday at-bats. His performance on Opening Day was certainly a good start.

“It’s exciting, but I don’t want to think too far out,” Pinder said. “Just come to work and, if I’m in the lineup, go play.”