SANTA CLARA, Calif. -- Through his first 23 NFL starts, San Francisco 49ers quarterback Brock Purdy has had his share of bumps in the road, most notably the torn ulnar collateral ligament in his right elbow suffered during last season's NFC Championship Game.
But Purdy had never had the type of on-field struggles that he experienced Monday night against the Baltimore Ravens. Purdy threw a career-high four interceptions, including three in the first half, and the Niners finished minus-5 in turnover margin on the way to a 33-19 loss that dropped them to 11-4 on the season.
"He's played this long, he never had a game like this," 49ers coach Kyle Shanahan said. "It's pretty unusual. That's the reality of the NFL. I'm not saying it's bound to happen but wish he didn't have as many picks today."
Purdy finished 18-of-32 for 255 yards with no touchdowns for a passer rating of 42.6, the worst of any start in his career. His night ended early when he departed in the fourth quarter after sustaining a left shoulder stinger.
By the time Purdy reached his postgame news conference, he already was pondering how things went awry against the Ravens and how he'd bounce back from such a rough outing for an away date with the Washington Commanders on Sunday.
"It's the NFL," Purdy said. "We have some opportunities coming up, and we still got two games left in the regular season before we get into playoffs. For me, [I'm] trying to look at the big picture of what we're trying to do, what our team goals are. But at the same time, I have to look myself in the mirror and ask myself why or how that happened and why I made those decisions?
"Our team came ready to play, and for me to make some decisions like that ... it's not fair to these guys. I have to realize that and understand that, and I have to get better for my team."
Purdy started well enough, as his third pass of the night was a strike to tight end George Kittle for a 58-yard gain to Baltimore's 28-yard line. He followed with another completion to Kittle for 13 yards. It was mostly downhill from there.
On first-and-10 at Baltimore's 15-yard line, Purdy forced a pass to wideout Deebo Samuel that Ravens safety Kyle Hamilton stepped in front of for an interception.
Purdy said he thought Samuel had flashed open but that he should have continued through his progression and checked the ball down instead.
"I thought the first one was the big mistake," Shanahan said. "And the other three were pretty unfortunate for him."
Each of Purdy's subsequent interceptions came with some sort of hit or deflection from the Ravens' defense.
The second pick was deflected into the waiting arms of cornerback Marlon Humphrey.
The third came when Purdy attempted to make something happen on a throw for Kittle during a scramble drill after running back Christian McCaffrey had been flagged for a chop block. Purdy said he was aware of the flags and had a feeling the penalty was on the offense, terming the decision to try the throw across his body "very dumb" because he made a bad situation worse.
That made Purdy the first NFL player to throw three interceptions in the first half of a game this season and the first 49er to do so since Nick Mullens in 2018. Purdy's four-interception outing was the first by a Niners quarterback since Colin Kaepernick did it in 2015.
With 8:19 to play in the fourth, Purdy took a sack from Ravens pass-rusher Jadeveon Clowney. Purdy briefly departed last week's win at the Arizona Cardinals with a shoulder stinger and endured a similar pain when Clowney took him down. The signal-caller jogged off the field and quickly headed to the blue medical tent as Sam Darnold replaced him.
Purdy potentially could have returned to the game, but Shanahan opted to keep him out in large part because the Niners' offensive line was down three players, including starting left tackle Trent Williams (groin) and left guard Aaron Banks (toe).
"I know he's disappointed not being able to finish it there, but getting that stinger again, I just wanted to keep him out of there," Shanahan said of Purdy.
Williams was injured while attempting to tackle linebacker Patrick Queen after Purdy's fourth interception. Despite his best efforts, Williams did not return. He is scheduled for an MRI on Tuesday. Williams declined to speak at length after the game but told reporters in the locker room, "I'm good. I'll be all right."
Purdy's career-low 42.6 passer rating followed a six-game span in which he had a 138.1 rating -- the highest in NFL history over a six-game stretch, according to the Elias Sports Bureau.
Now, Purdy will have a short week to prepare for the Commanders.
One silver lining the Niners were quick to point out after Monday's loss is that they still control their NFC playoff positioning. Wins against Washington and the visiting Los Angeles Rams on Jan. 7 or one victory and some help would give the 49ers the NFC's No. 1 seed, home-field advantage and a bye during the first weekend of the postseason.
But first, San Francisco will get a look at how Purdy rebounds following the worst outing of his two campaigns.
"I got to ask myself, 'All right, who are you?'" Purdy said. "'What do you stand for? Who are you when things are good? Who are you when things don't go your way?' It's easy to be riding high and thinking you're the man when things are going well, winning games and all that kind of stuff. And you don't really see a whole lot of adversity in some games and whatnot, and this is the reality of the NFL.
"I obviously have to look myself in the mirror, watch the plays ready to get better, make some cleaner decisions, help my team put up points and score and protect the ball. And when things don't go my way, it's understanding I can't be acting out. I have to be real with myself and be better, but I want to be the same guy every day. I want to be consistent in what I do and how I do things; whether things are going well or not, I know who I am, and I'm not going to waver from that."