For the second straight week, Christian McCaffrey struggled to have a significant impact running the ball for the San Francisco 49ers.

After gaining just 39 yards on the ground in his season debut against the Tampa Bay Buccaneers last week, McCaffrey went for 79 yards on 19 carries, an average of 4.2 yards per rush as the 49ers let slip a fourth-quarter lead in a 20-17 upset loss to the Seattle Seahawks.

McCaffrey's lack of explosiveness coming off bilateral Achilles tendinitis was clear throughout as he produced just two runs over 10 yards in the entire game.

Yet McCaffrey played all but four of the 49ers' offensive snaps as Jordan Mason and Isaac Guerendo were largely kept on the sideline despite both impressing while McCaffrey was on injured reserve.

Mason's two carries went for 13 yards. Guerendo did not have a rush attempt. McCaffrey's runs averaged minus 0.06 Expected Points Added. On his very small sample size, Mason averaged 0.41 EPA per rush.

It is difficult to read too much into Mason's numbers given his lack of game time, but he clearly looked like the more explosive runner, and there is evidence to suggest both he and Guerendo might have enjoyed greater success in breaking long gains against Seattle.

Guerendo went into Week 11 ranked eighth among all running backs with at least 20 rush attempts in EPA per attempt, per Sports Info Solutions. The rookie fourth-rounder had a game-clinching 76-yard rush in the Week 6 road win over Seattle, a game that saw Mason break a 38-yarder. Even with his now severely reduced role, Mason is tied for 10th in the NFL with 19 runs of at least 10 yards.

All those numbers make the 49ers' extreme reliance on McCaffrey look all the more bemusing. For his part, reigning Offensive Player of the Year McCaffrey is confident an explosive performance similar to those he consistently produced in 2023 is on the horizon.

Asked in his postgame press conference if he is close to breaking a long run, McCaffrey replied: "Yeah."

He added: "I can be a lot better. I feel like I can be a lot better. To miss time with an injury is always tough, it's not an excuse, but I know I can be a lot better. I feel it. It's coming."

The 49ers are in a difficult spot. History suggests it would be wrong to doubt McCaffrey, but him recapturing his explosive best this season is far from a guarantee.

This season, there is compelling evidence to suggest that, on the ground at least, Mason and Guerendo are better bets to produce the long runs that could have made a huge difference against Seattle.

McCaffrey is the better option as a passing game outlet and is superior to both Mason and Guerendo in pass protection but, as he continues to try to knock the rust off, it's clear he has no decided edge over either of that duo as a runner.

Now 5-5 and with their playoff hopes hanging by a thread, the 49ers don't have time to wait for McCaffrey to return to top form. They need a dynamic running game for the Kyle Shanahan offense to work at peak efficiency. McCaffrey may be confident he is about to imminently start ripping off huge gains, but the 49ers would be wise not to believe him and work both Mason and Guerendo back into the ground game.

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They’re facing an uphill battle.