SANTA CLARA -- The 49ers just beat the Las Vegas Raiders 38-17. Here are the 49ers' grades for this performance.

QUARTERBACK: B

Brock Purdy played well, but hasn't played like an MVP candidate since Mike Evans went down. Today, he scrambled extremely well, but that's partly because he didn't trust his receivers, with the exception of Jordan Watkins (more on him in a minute). Purdy usually lets it rip before receivers have made their breaks. Now, he's holding the ball longer than ever and using his legs more than he probably would like to. Because when he does let it rip, and Evans isn't on the field, Purdy often gets intercepted. Either Evans needs to come back soon, or the 49ers need to trade for another wide receiver. Otherwise, Purdy will struggle against decent defenses. Fortunately for him, the Raiders' defense is laughable.

RUNNING BACKS: A-MINUS

Christian McCaffrey averaged just 3.8 yards per carry against a horrendous run defense, but he also scored two touchdowns -- one on the ground and one through the air. And he wasn't even the 49ers' leading rusher. That was Kaelon Black, who averaged a whopping 6.4 yards per carry. The more the 49ers give him the ball, the better their offense performs, because the 49ers are a run-first offense, and they can't control the game with their rushing attack if they use just one running back. Today, they ran the ball 43 times. They couldn't have done that without Black.

WIDE RECEIVERS: C-PLUS

Jordan Watkins committed two penalties and still was the only good wide receiver in the game for the 49ers. He caught four passes for 86 yards and a touchdown, and looked like a quality complementary receiver, but not a go-to guy. Not someone who could catch 10 passes in a game. Against better defenses, the 49ers will need Mike Evans or some other wide receiver they could add via trade in the next day or two (George Pickens? Brian Thomas Jr.?). Demarcus Robinson certainly doesn't count. Neither does Deebo Samuel.

TIGHT ENDS: C

George Kittle had four catches for 58 yards. Luke Farrell had zero catches yet again. Hard to believe the 49ers gave him a three-year deal just to make no impact. Thank goodness they still have Kittle.

OFFENSIVE LINEMEN: B

They gave up just one sack and helped pave the way for the offense to gain 190 yards on the ground. Still, they got stopped on a quarterback sneak because Jake Brendel and Dominick Puni generated no movement at the point of attack against a junior varsity defensive line.

DEFENSIVE LINEMEN: C-PLUS

The 49ers' defensive linemen recorded four tackles for loss and helped shut down the Raiders' anemic run game, but they never sacked Kirk Cousins, who is extremely sackable. Fortunately for the D-linemen, Cousins threw three bonehead interceptions. Still, the 49ers probably were expecting Nick Bosa and DeForest Buckner to superchange their pass rush, but they didn't. Neither made a big impact, and the 49ers now haven't recorded a sack in their past two games. In addition, they lost rookie defensive tackle Gracen Halton to a season-ending leg injury with fewer than four minutes left in the game while leading by 18 points. That hurts. The 49ers might need to trade for another pass rusher before Tuesday's deadline.

LINEBACKERS: A-PLUS

Fred Warner might be the best player in the NFL. Today, he recorded just 5 tackles, but he forced a fumble, recovered a fumble, and jumped over the pile at the goal line to stop a quarterback sneak for a two-yard loss. That final play was one I've never seen a linebacker make. I didn't know it was physically possible to stop a quarterback for a two-yard loss on a sneak. Warner invents new ways to be great every week. And he isn't the only good linebacker on the team. Dre Greenlaw had three tackles for loss, and rookie Jaden Dugger had a pick-six.

DEFENSIVE BACKS: B-PLUS

Renardo Green and Malik Mustapha each intercepted Cousins once, which is impressive considering Cousins wasn't under much pressure. Still, Cousins gift-wrapped those interceptions. Collectively, this group gave up 7 catches for 111 yards and a touchdown to Brock Bowers, the only legitimate weapon on the Raiders. You'd like to think a Super Bowl-caliber defense could shut down one player, even if he's great. In addition, the 49ers gave up 3 catches for 37 yards to backup tight end Michael Mayer, who fumbled at the goal line and was flagged for a ticky-tack offensive pass interference penalty in the end zone that negated a touchdown catch. The 49ers seem to have issues covering quality tight ends. Something to monitor the rest of the season.

SPECIAL TEAMS: B-MINUS

Eddy Pineiro made all of his field-goal attempts and extra points, but the kickoff coverage team gave up a 54-yard return. Unacceptable.

COACHES: B-PLUS

Raheem Morris' defense forced five turnovers, but most of them were gifts from the Raiders, who stink. It's alarming that Morris' defense generated minimal pressure on Cousins and struggled to cover the Raiders' two tight ends, even when they lacked a viable threat at wide receiver and running back. The 49ers should consider trading for a safety before the deadline because Ji'Ayir Brown is a liability.

On offense, Kyle Shanahan won the game because he finally trusted his young weapons, unlike two weeks ago when the 49ers lost to the Falcons, who are worse than the Raiders. In that game, Shanahan refused to feature Watkins and Black, and so the 49ers lost. Today, Watkins was the leading receiver, and Black was the leading rusher. And as a result, the 49ers offense scored 31 points. Good to see Shanahan honestly size up his performance during the bye week so he could improve. Now, he needs to make another trade.