FOXBORO – On the whole, Thursday night was a half-decent showing for the Patriots’ much-maligned offensive line.

Starting quarterback Jacoby Brissett took just one hit in his three series of work. Second-string rookie Drake Maye was kept clean until his final snap of the night, when Eagles edge rusher Nolan Smith bounced off a Kevin Harris chip block, shot past left tackle Vederian Lowe and crunched the first-round draft pick for a sack.

Those linemen didn’t have to face Philadelphia’s formidable defensive starters, however, who got the night off after manhandling the Patriots during Tuesday’s ugly joint practice. And after the preseason matchup at Gillette Stadium, which Philly won 14-13, head coach Jerod Mayo made clear he’s concerned about New England’s depth up front.

“There were definitely some ups and some downs,” Mayo said. “I would say there’s a dramatic drop-off, not really physically, but just knowing what to do, between the first line and the second and third guys. They have to get better as a whole, as a unit. They just have to get better.”

And that’s a top unit that’s cycled through a slew of tackles this summer, struggling to find a viable starting five. For the Patriots’ other internal options to be not just worse, but “dramatically” worse is a real problem with the start of the regular season a little over three weeks away.

Finding five trustworthy O-line starters is important, but depth is crucial, too. Injuries are inevitable, especially in the trenches. The Patriots trotted out more than a half-dozen different starting combinations in each of the last two seasons. It’s rare for a team to start the same tackles, guards and center in all 17 games.

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The Patriots’ current top unit (from left: Lowe, Sidy Sow, David Andrews, Mike Onwenu and Chukwuma Okorafor) remained intact through Maye’s first series Thursday night, then began subbing. Lowe and Sow both played into the second half, with Nick Leverett and rookies Layden Robinson and Caedan Wallace replacing Andrews, Onwenu and Okorafor, respectively. Those five were on the field for the Patriots’ lone touchdown: a 4-yard option keeper by Maye shortly before halftime.

The protection devolved late in the game, with Joe Milton III taking two sacks and Bailey Zappe’s two-minute drill ending on a botched snap by reserve center Liam Fornadel.

“One, we’ve all got to be on the same page, right?” Andrews said postgame. “Assignments, things like that. It all starts there. Get people going in the right way, usually you can have some success. We’ve just got to try to get better as fast and quick as we can. Especially young guys, but old guys, too. We’re all pushed up three weeks or whatever it is until the opener, and it’s a race — a race not just those three weeks, but throughout the year. Who can get better?”

The Patriots’ new-look offense won’t be successful without capable blocking, but Mayo claimed the persistent O-line qualms won’t factor into his decision on when to elevate Maye to starting quarterback.

“For me, we always talk about competition, and that’s at all spots,” the head coach said. “So even if Drake beats out Jacoby, I mean, he earned that role. And we don’t really take that into consideration when he’s ready to go. If he’s better than Jacoby, then he’ll play — he’ll start.”