The 49ers have to find a new left guard to replace Aaron Banks.

Banks signed this offseason with the Green Bay Packers. The 49ers originally drafted Banks with a second-round pick, so there’s a distinct possibility that they’ll use another second-round pick to replace him.

That’s why NFL.com’s Chad Reuter projects the 49ers to pick Ohio State guard Donovan Jackson in Round 2.

“Jackson has the athleticism for all tasks as an outside-zone blocker,” writes NFL.com analyst Lance Zierlein. “He is also able to accelerate and lead the way on long pulls or counters. He leans against stunting/slanting fronts, and he can be tardy in opening his hips and activating his feet for recoveries. He’s long but punches with wider hands and struggles to consistently maintain his edges when mirroring. Overall, Jackson has the measurables, power and movement for any scheme as a starting guard.”

Jackson would be a great pick if the 49ers are looking for a guard who’s quick and agile like Dominick Puni, their third-round pick last year.

But if they’re looking for someone like Banks, they might draft someone with a bit more mass and power considering Banks weighs 325 pounds and Jackson weighs 315 pounds.

Unfortunately for the 49ers, Arizona’s Jonah Savaiinaea isn’t available in this mock draft — the Raiders took him with the 37th pick. He would be a perfect replacement for Banks. Jackson is a solid second option.

Still, I find it hard to believe that the 49ers won’t address their defensive line with one of their first two picks.