This is totally (and literally--I'm sitting in my rocking chair) "arm-chair" GM'ing, but I would love to see us take a chance on this guy:
Phil Haynes, who's patiently waiting for another NFL opportunity on the Seahawks practice squad. My man has been at or near the top of The PSPR for weeks now for a reason. The nearly 6-foot-4, 320-plus pounder tested like a high-caliber athlete at the 2019 combine after an illustrious, 47-start career at Wake Forest. While he's battled injuries over the past two seasons after being Seattle's fourth-round pick, he does have playoff experience, believe or not. Haynes played left guard in the Seahawks wild-card round loss to the Packers in Green Bay as a rookie. On 41 pass-blocking snaps, he surrendered just two hurries of Russell Wilson. And this past preseason, Haynes rocked. One pressure allowed on 71 pass-blocking snaps. If the Bills actually do feel the depth of their guard position has to be improved, Haynes needs to be their guy.
If not him, then go get DeCastro if he is ready to get back to football. We know that is an upgrade.