According to the HD Room the two mystery men in The Walking Dead mid-season premiere 'Nebraska' clip have been identified as actors Aaron Munoz and Michael Raymond James.
Munoz will play Tony, one of two new survivors that will cross paths with Rick's group. James' character's name is still unknown. Both roles are being labeled as "guest stars" so these characters could potentially only be around a couple episodes or less.
The Walking Dead mid-season premiere is set for Sunday, February 12 at 9/8 central on AMC.