A number of former Dallas stars are expected to return to the revamped TNT series as part of a storyline involving JR Ewing's funeral.
Larry Hagman (JR) passed away last month, with his character's absence now being written into the show's second season.
Principal - who played Pam Ewing on the original Dallas between 1978 and 1987 - is on the producers' wish list but is yet to sign up for a return appearance, according to TVLine.
Dallas showrunner Cynthia Cidre previously claimed that the character of Pam was unlikely to return to the show, arguing that TNT's revamp "needed a breath of fresh air".
"I personally have not reached out to [Victoria Principal] and to my knowledge the studio hasn't either, and I don't think she has any interest in it," Cidre said in October.
Principal recently paid tribute to her late former co-star Hagman, calling the actor "unforgettable, and irreplaceable".
Dallas season two will premiere on January 28 in the US, with new episodes expected to air on Channel 5 in the UK later in 2013.
> Larry Hagman's career: 'Dallas', 'I Dream of Jeannie' - video
> Larry Hagman 1931-2012: Obituary
Watch a trailer for Dallas season two below:
Photo gallery - Larry Hagman's TV life in pictures:
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