Some of us were waiting until Sunday night to start judging in earnest the Vikings’ overall strength, or lack thereof.

That’s because Sunday night’s preseason home game against the 49ers finally would be our first look at the five guys who presumably will start on the offensive line when the regular season opens.

Those five guys — left tackle Riley Reiff, left guard Alex Boone, center Nick Easton, right guard Joe Berger and right tackle Mike Remmers — did indeed take the field for 15 snaps together.

And now it’s Monday and — with all due respect to Taylor Heinicke’s winning two-point conversion run with no time remaining in a 32-31 victory — some of us are admitting that, yeah, it’s reasonable to be worried.

This season, like last season, will rise or fall with the offensive line. And this revamped line had an all-too-familiar look of constipation to it.

“I thought it was sporadic,” Vikings coach Mike Zimmer said.

In 15 snaps, the presumed No. 1 line helped the offense net 36 yards (2.4 per play) with three first downs, five plays for losses, no points, a penalty on third down and three sacks, two of which the line was responsible for. And that came against a 49ers team that posted an NFC-worst 2-14 record and an NFL-worst scoring defense (30 points allowed per game) a year ago.

On just their fourth possession, the Vikings started subbing linemen, indicating that the battle at center might not be over. Rookie Pat Elflein took over at center, while Easton moved to left guard and Rashod Hill came in to play left tackle. Zimmer wouldn’t say if he has picked his starting center yet.

The Vikings’ first possession started with losses of 5 and 7 yards.

Neither loss was the line’s fault. Running back Dalvin Cook was dropped on a quick throw into the right flat. On the next play, he inadvertently knocked the ball out of Bradford’s hands, causing Bradford to fall on it for a sack.

The next play — a third-and-23 situation — was Bradford’s first deep drop with his new line. The line held up well, allowing Bradford to throw a 19-yard strike to Laquon Treadwell. But it wasn’t enough to avoid a three-and-out.

The second possession started with two Cook runs for 9 yards, including a nice power sweep left for 6 yards. But then things started to fall apart up front as the 49ers gave the Vikings some looks they weren’t expecting in a preseason game. Bradford was knocked down on three of the next five snaps, including back-to-back sacks that forced a punt.

The last two sacks showed the Vikings have some work to do against blitzes and stunts.

On the first sack, left end Arik Armstead and safety Eric Reid ran a stunt that confused Remmers and tight end David Morgan. Reid broke free inside while Armstead got the sack by looping to the outside.

“That’s what’s tough about the preseason,” Remmers said. “You never know quite what they’re going to do because you don’t game plan for it. They brought some unique looks, but we still need to be able to pick those up better than we did.”

On Bradford’s last sack, Remmers got overpowered and pushed off balance by end Elvis Dumervil.

After that play, offensive coordinator Pat Shurmur went to quicker throws, probably to preserve Bradford’s health. That was a familiar survival tactic Shurmur used a year ago.

“Hats off to the 49ers; they were smart in bringing their safeties down late,” Boone said. “They did a good job of disguising what they were doing. It was so late in the cadence that nobody could make any [adjustment] calls.”

Remmers made another mistake on the third possession. With his back leg too far into the backfield, he was flagged for illegal formation on third-and-4. The drive ended a play later when Bradford checked down to Stefon Diggs, who was dropped for a 2-yard loss.

“It was nice to have everybody out there on the line,” Boone said. “But we need to get a lot better.”

Until then, yeah, it’s reasonable to worry.