Tramon Williams and Sam Shields, the Packers’ primary cornerbacks, have each been vulnerable in coverage this season. Williams has allowed an 88-1 opposing passer rating and has allowed four touchdowns to just three interceptions. Shields has been better, but not by enough — he’s allowed a 72.7 rating, and allowed four touchdowns to four picks. Both Williams and Micah Hyde have allowed opponent passer ratings of more than 100 in the slot, which could bode well for Anquan Boldin. The veteran receiver has lined up 221 times in the slot this season, and he absolutely killed the Packers in that Week 1 game — he caught 13 passes for 208 yards and a touchdown in his 49ers debut.