"Tyreese is not necessarily a good guy who simply joins Rick’s team and fights against the Governor. He’s a wild card," Mazzara told Entertainment Weekly. "He’s an interesting character and his priority is keeping his own group safe. I think viewers will be surprised by the twists and turns in the Tyreese story."
But given that Tyreese is still, in the context of the show, a newcomer, it's Mazzara's analysis of Daryl's current conflict that really raises eyebrows.
"Daryl has spent the last year with Rick and this group, and he has worked very hard to wrestle his past demons and to become a very, very valuable member of Rick’s band," the showrunner said. "So much so that we saw him step up as the number two after Lori’s death. He’s really the one who takes leadership of the group when Rick is lost in the tombs and the boiler room after Lori’s death. Now he’ll have to make choices after discovering that his brother is alive and his brother is on the opposing side. Daryl is caught in the middle and has to make choices. Can he try to bring everyone together, or does he pick a side, or does he have to go up against Rick in some way? I think it’s a very interesting arc. Norman Reedus is fantastic to work with and I think he’s got some pretty amazing work in the back half of the season."
In the course of the last couple of months of discussion, this is the first time we've heard anyone seriously suggesting that Daryl might actually end up squaring off against Rick and his group. It's still extremely unlikely, but that it's even a concept they're interested in playing with is interesting.