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Brock Purdy’s return Sunday immediately stabilized the 49ers’ offense and could serve as a turning point in a season that’s been defined by high-profile injuries.

There’s no doubt that Purdy raises the 49ers’ ceiling and lends credibility to their playoff hopes, but he’s not the most irreplaceable player on the team. He’s not even the most irreplaceable player in his own backfield.

That distinction belongs to Christian McCaffrey, who surpassed 700 rushing yards and 700 receiving yards on the season Sunday with a 13-carry, 81-yard effort on the ground and a five-catch, 40-yard performance through the air.

Another rock solid McCaffrey performance was rightly overshadowed by Purdy’s efficient 200-yard, three-touchdown afternoon back in his home state of Arizona. 

There’s so much emphasis on quarterback play in the NFL – and so much attention that comes from signing a five-year, $265 million contract – that every Purdy performance is closely scrutinized. McCaffrey, meanwhile, can pop off for 6.2 yards per carry and fly under the radar.

At 7-4 and with three more winnable games up next in the easiest part of the 49ers’ schedule, Purdy could easily find more of a rhythm and turn the offense into one of the NFL’s most dangerous units entering January. 

But that is possible only when McCaffrey is at his best, as he’s been all season long. 

Playing in an offense that’s mostly been guided by backup Mac Jones and running behind an average-at-best line, McCaffrey is turning in one of the most statistically impressive seasons for any non-quarterback in recent years. He’s on pace for his third season with 2,000-plus scrimmage yards and could become the first player in league history to reach 1,000 rushing and receiving yards in the same season twice in his career. (McCaffrey did this in 2019 with the Panthers.) 

Entering Sunday’s game, McCaffrey’s 69 catches ranked second in the NFL. No other running back had more than 50. His 180 carries also ranked second in the league. Only three other backs had more than 150. His usage is off the charts, and even though the 49ers tried to ease the burden Sunday, McCaffrey still finished with 18 touches and more than 120 yards from scrimmage. 

When Purdy went down at the beginning of this season, Jones stepped in and performed admirably. Jones isn’t the same caliber of quarterback that Purdy is, but he elevated the offense and kept the 49ers in the playoff hunt.

When McCaffrey went down last season, no one could fill his void. Jordan Mason and Isaac Guerendo were equipped as running backs, and George Kittle’s reception total spiked because of his involvement in the short passing game, but there’s no player who can match McCaffrey’s versatility.

Should McCaffrey be an MVP candidate? Perhaps, but that’s a discussion for another day. Is he the 49ers’ MVP? Absolutely, and because Purdy missed so many games, there’s no one else in the running. 

Purdy’s return changes so much for the 49ers. But it doesn’t quite change how reliant this team is on McCaffrey, who was able to put the offense on his back during the quarterback’s absence.