TNT had announced that "Private Practice" star Kate Walsh would help reveal the names, however, the network said Wednesday that Tripplehorn, star of the HBO series "Big Love," would be sharing announcing duties with Howard, who was seen this year in the high-profile films "The Brave One," "The Hunting Party" and "August Rush."
The SAG Awards nominations in five film and eight television categories are to be revealed Thursday in the SilverScreen Theater at the Pacific Design Center in West Hollywood, Calif.
The nominations announcement will also be telecast live on TNT and Web-cast live on TNT.tv and TBS.com.
The 14th Annual Screen Actors Guild Awards, the only industry accolades devoted to actors honoring actors, will be simulcast live on TNT and TBS Jan. 27 from the Shrine Exposition Center in Los Angeles, TNT said in a statement.
2014: The Year in Music [PHOTOS]