The 49ers thought the return of Christian McCaffrey would solve their problems on offense. Instead, they’ve gotten worse since he came back.

In the three weeks McCaffrey has played this season, the 49ers have scored just 16.7 points per game. In the eight weeks he missed, the 49ers scored 26.3 points per game. Big difference.

Forcing McCaffrey back into his role as the featured weapon on offense has had a negative impact on the entire team. And that’s no knock on McCaffrey. He deserves credit for battling back from bilateral Achilles tendonitis and playing with no offseason. He clearly isn’t in football shape, he lacks burst and elusiveness but he’s a captain and the 49ers’ season is slipping away, so he’s trying to step up.

Adding McCaffrey to an offense that was averaging more than 26 points per game without him should be a good thing. But to get McCaffrey on the field, the 49ers have buried running backs Jordan Mason and Isaac Guerendo who were playing extremely well. So suddenly, the 49ers running game has become a big weakness.

So far this season, McCaffrey is averaging just 3.5 yards per carry. Meanwhile, Mason is averaging 5.1 yards per carry and Guerendo is averaging 6 yards per carry. As a trio, they could be elite. But since McCaffrey returned, Mason has only six carries and Guerendo has just one. They’re not being used as a trio.

If the 49ers find a way to use all three running backs, their offense should improve no matter who their quarterback is.