Brock Purdy will be the main target of external criticism after the San Francisco 49ers dropped a second straight game in their 22-17 loss to the Minnesota Vikings on Monday.

But several of the 49ers' stars were quick to take their share of the blame after failures of execution in several areas saw them drop to 5-2.

Purdy threw an interception to Camryn Bynum on each of the 49ers' final two drives with a chance to take the lead, his mistakes on those plays rounding off a night in which San Francisco made a host of key errors.

Christian McCaffrey scored both of the 49ers' touchdowns, extending his streak of consecutive games with a score to 16, but his focus was on his fumble in the red zone on the Niners' first offensive series after Kirk Cousins was picked off by Charvarius Ward.

"I can't make those mistakes early in the game," McCaffrey told a post-game press conference. "I made a bad mistake that I believe cost us the game."

McCaffrey is perhaps being overly harsh on himself, as a defensive performance that saw San Francisco give up 452 net yards and allow the Vikings to convert eight of their 13 third-down attempts certainly played a huge role in the 49ers slipping to another upset loss.

The 49ers did not register a sack of Cousins, much to the frustration of Nick Bosa and a defensive line that has a reputation as one of the best and deepest in the NFL.

"We have a lot of good players on the D-Line and a lot invested in it," said Bosa. 

"We have to make the plays when they're there. I need to do that with the kind of player I'm supposed to be."

Bosa is of course the reigning Defensive Player of the Year, the biggest star on a defense filled with Pro Bowlers and All-Pros at all three levels.

Yet the transition to a new defensive coordinator in Steve Wilks, whose decision to send a six-man pressure in the dying seconds of the first half on a play that resulted in a Jordan Addison touchdown will attract significant scrutiny, has not looked as smooth as it did through the first five weeks of the season.

All-Pro linebacker Fred Warner, however, dismissed suggestions the change to a coach who sends blitzes more frequently is the reason for the recent downturn.

"Things are as similar as they've always been, we've just got to execute," said Warner. "We’ve got to find a way to win the grimy games.

"We’ve got a big game coming up against the Bengals at home. It’s a must-win."

Instant reaction: Brock Purdy fails to rise to the moment as 49ers lose second straight

Another ugly loss.