As “The Walking Dead” reaches its midseason finale, two N.F.L. rivals try to keep their playoff hopes alive.

What’s on TV

GREEN BAY PACKERS VS. MINNESOTA VIKINGS 8:20 p.m. on NBC. One of the biggest rivalries in professional football comes to Sunday Night Football. Both teams have had mixed seasons so far and are each coming off losses. In their previous meeting, in September at Lambeau Field, they fought to a rare tie. With the season more than halfway gone, this showdown may determine the fate of both teams this year. The Packers’ star quarterback, Aaron Rodgers, will have to be in fine form to overcome the Vikings’ stout defense, while Dalvin Cook will look to bounce back from his injuries to reinvigorate the Vikings’ running game.

THE WALKING DEAD 9 p.m. on AMC. The long-running and much-loved series reaches its midseason finale. After learning from a recently awakened Rosita that Eugene is still stranded in the wilderness after their encounter with a strange group of walkers, Daryl and Jesus lead a small group to rescue him. But the risks of their mission are greater than they know — an unexpected threat may put the group in even greater danger than usual. These walkers are not the usual shuffling zombies. They communicate and seem to have a mission.