Nick Underhill’s concern with Saints O-Line might be “heightened”

For context, let's acknowledge that only one starter (Penning) played that game. It's fair to say our depth looks poor, and unfortunately it's more probable than not that we'll need to rely on depth. But we'll also have the loser of the Hurst/Peat position battle ready to step in at G/T should someone go down (neither of whom played Sunday).
Not only that, but Hurst and Peat can play guard or tackle, and Ruiz can play center fairly well if needed. The real questions along the line are related to the development of Penning as a LT and Saldiveri as a backup RG sooner than later. Both are young guys, so they're likely to get better and better with reps.

There's a significant concern if 3+ starters are down at once, but most every OL in the league would struggle under those circumstances.