Eric and Bill (Stephen Moyer) have had a strained relationship in the past but Skarsgård told E! Online that they will have a different dynamic in the new episodes.
"We call it season of the bromance," he explained. "We just started [filming] and we're on episode four of season five."
Skarsgård added: "I have a lot with Steve this year... Eric is very intrigued by Bill now."
Stars including Peter Mensah and Christopher Meloni have signed up for roles in the fifth season of True Blood.
The show is expected to return to HBO later this year. The fourth season is currently airing in the UK on Sundays at 10pm on FX.
Watch a teaser trailer for the fifth season of True Blood below: