How the 49ers Will Replace Trent Williams If He Leaves

The 49ers might re-sign Trent Williams when free agency starts. But if they don't, they need a Plan B.

Kyle Shanahan may have revealed his Plan B last year after the draft, when a reporter asked him if he ever seriously considered drafting Tristan Wirfs in Round 1. At that point, a deal for Williams wasn't in place.

But Shanahan said taking a left tackle in Round 1 never was their plan. “One thing that was really cool was if the Washington deal didn’t go through, one of our Plan Bs was to try to draft Colton McKivitz there in the fourth round. Then we did end up getting Trent, and to still be able to get (McKivitz) in the fifth round was a hell of a deal. We felt really excited about how today went.”

This quote it fascinating. It suggests Shanahan sees an elite left tackle as a luxury, not a necessity. He was prepared to start a freaking rookie Day 3 pick at left tackle last season.

Obviously, Shanahan won't start McKivitz at left tackle next season -- he's not good enough to start at any position, let alone left tackle. He was a flop at guard. He needs time to develop.

But Shanahan still might go with an in-house option at left tackle. And his best in-house option is Daniel Brunskill.

Brunskill was the second-best tackle on the 49ers last season -- better than Mike McGlinchey. Brunskill should have taken his job, but the 49ers are in denial about McGlinchey, so Brunskill played guard and center.

Brunksill has given up just five sacks in his entire career, and has played well against Aaron Donald twice. If Williams leaves, don't be surprised if Brunskill is the 49ers starting left tackle in 2021.