The Bills seem to have everything to succeed, but for some reason, they've so far failed to do so. Following a second consecutive exit in the divisional round, Buffalo is facing many changes ahead of a demanding 2023 NFL season.

Defensive coordinator Leslie Frazier is taking a year off from football, linebacker Tremaine Edmunds is leaving for the Chicago Bears, and veteran quarterback Case Keenum is going back to Houston to play for the Texans.

The 35-year-old's departure is not meaningless, since it leaves a significant vacancy in the depth chart. With Keenum gone, the Bills will probably have to look for another backup to Josh Allen.

Potential backup QBs for Josh Allen at Bills

Even though Allen practically never leaves the field, you can never take anything for granted in this league. With many viable options in the open market, it would make sense if the Bills go after a veteran signal-caller capable of delivering results if needed.

Marcus Mariota

Todd Kirkland/Getty Images

Todd Kirkland/Getty Images

Marcus Mariota's best days are far behind him, but he could be useful as QB2. At 29, the former Falcons quarterback is no longer a starter but it's safe to say that as a backup he might be able to stay in the league for many years. If something happens to Allen, Mariota can provide mobility and enough experience to lead the offense.

Andy Dalton

Tim Nwachukwu/Getty Images

Tim Nwachukwu/Getty Images

Andy Dalton has somehow managed to start more games than predicted in the last few seasons, but it's hard to see any opening for him that is not a backup job at this point. After his last year with the Saints, Buffalo may trust in him as an insurance for Allen.

Jacoby Brissett

Jason Miller/Getty Images

Jason Miller/Getty Images

Following his decent outings for the Browns during Deshaun Watson's absence last year, Jacoby Brissett shouldn't be lacking in suitors this offseason. But a starting job may not be on the cards for him anymore, so it looks like the Bills would have to give him a reason to prefer being a backup in Buffalo than elsewhere.