An injury-filled season for the San Francisco 49ers has hit the backcourt the hardest, as both Christian McCaffrey and Jordan Mason are now on injured reserve and potentially out for the season. So how do the Niners plan to replace their two injured lead backs? A strong dose of Isaac Guerendo, according to ESPN insider Jeremy Fowler in a column Saturday.

“RB Isaac Guerendo is ready to carry a heavy workload for San Francisco over the final five games,” Fowler wrote. “This could lead to something promising. He weighs 220 pounds and weighs 4.33, a rarity for running backs. He’s more comfortable in it. “San Francisco’s offense is better than it was at the start of the season, and he’s ready for 20-plus carries per week as a featured player (depending on how the game goes and what Kyle Shanahan wants to do, of course.).”

The Niners added some depth at running back this week by claiming Israel Abanikanda off waivers from the Jets and signing Patrick Taylor Jr. from the practice squad to the active roster. The team also re-signed running back Ke’Shawn Vaughn to the practice squad and added him to the roster for Sunday’s game against the Bears.

There’s a chance one of these three players gets a few snaps on offense, but under head coach Kyle Shanahan, the 49ers tend to give a single halfback the majority of carries. That was the case with Mason when he was fully healthy during his stellar start to the season. When McCaffrey returned from his Achilles tendon injuries, he took over and played the vast majority of snaps at running back.

Now, with McCaffrey out for the remainder of the regular season with a PCL injury and Mason out for at least four weeks with a severe ankle sprain, expect Guerendo to be the main man for the Red and Gold Championship. So far this season, the rookie has 42 carries for 246 yards and two rushing touchdowns.

“I think he’s ready to go,” Shanahan said Wednesday. “…He had a late start due to injuries in pre-season. I thought he did well in those games, especially with his kick return against the Raiders, I think. He did some pretty good things when he first started, didn’t do many carries, had some ups and downs, but got better through it all. And then when he got the bulk of the runs — I want to say a little more compared to Seattle — he just got better, and he’s gotten better all year long.”

Guerendo and the 49ers will face the Bears on Sunday at 1:25 p.m. The game will be televised on Fox.