Deebo Samuel is gone and Brandon Aiyuk might never be the same after tearing his ACL, MCL and meniscus. Which means the 49ers need someone new to step up and become a factor on offense.

That player could be a wide receiver such as Ricky Pearsall, Demarcus Robinson, Jacob Cowing or Jordan Watkins. But the 49ers offensive line isn’t particularly good and probably won’t give Brock Purdy enough time consistently to push the ball down the field.

Last year, Purdy held the ball too long and forced it downfield too often, largely because Christian McCaffrey missed all but four games. Without McCaffrey on the field, Purdy’s efficiency dropped and his job became much more difficult.

Fortunately for Purdy, McCaffrey is healthy right now and figures to be a major part of the passing game as long as he’s on the field. But McCaffrey turned 29 last month — he’s old for a running back. The 49ers shouldn’t overuse him and wear him down during the long, grueling, 17-game regular season. They should preserve him as much as they can for December and January.

Which brings us to his backup, Isaac Guerendo. He’s a good receiver, too. The 49ers won’t have to change their offense significantly when he’s on the field because he can do a lot of the things McCaffrey does.

Guerendo is 6’0″, 221 lbs. and he runs a 4.33. He’s a freak. Last season, he caught 15 of 16 targets and averaged 10.1 yards per catch, which is a big number for a running back. For comparison, McCaffrey averaged 9.7 yards per catch last season.

Expect Kyle Shanahan to call screen passes and even the occassional deep shot to Guerendo, because he’s the most explosive player on the offense. He’s a threat to score a touchdown every time he touches the ball, kind of like a young Deebo Samuel.