Just yesterday we heard that forthcoming 'How I Met Your Mother' spinoff 'How I Met Your Dad' had added 'Workaholics' vet Anders Holm in a crucial, but only recurring role, while two regulars had yet to be cast. Now, 'Masters of Sex' and 'Heroes' vet Nicholas D'Agosto and likely 'Mixology' castoff Andrew Santino have officially joined the cast of 'How I Met Your Dad,' but is casting for the new MacLaren's gang finally complete?

According to CBS, D'Agosto will take the series regular role of Frank, coworker to Juliet ('Smash' star Krysta Rodriguez) who has something of a one-sided crush on series leading lady Sally (Greta Gerwig). Santino will play Danny, Sally's older gay brother and husband to Drew Tarver's Todd, though the role remains in second position to Santino's current gig with ABC's 'Mixology,' and will thus be billed as a "guest star" for the moment.

One might also expect that a regular gig with 'How I Met Your Dad' would take D'Agosto away from his current 'Masters of Sex' role, though when asked about the situation over Twitter, the actor would only respond "You'll have to tune in to #MastersofSex Season 2 to find out... :)."

Apart from Gerwig, Tarver, Rodriguez, D'Agosto and Santino, still uncast is the role of the narrating future Sally. Also worth noting is that where first it was thought that we’d meet at least some of the new cast in the final episodes of ‘How I Met Your Mother,’ ‘How I Met Your Dad’ will in fact film its own pilot independent of any of the established characters. ‘Up All Night’ creator Emily Spivey will head up the show creatively with ‘HIMYM’ producers Carter Bays and Craig Thomas, with Gerwig likely taking on writing duties as well. Unlike 'HIMYM,' production beyond the pilot of 'How I Met Your Dad' would also move to New York.

Well, what do you think? Do Nicholas D'Agosto or Andrew Santino make the concept of ‘How I Met Your Dad’ any more palatable to you? Who would you like to see join the potential ‘How I Met Your Mother’ spinoff, to replace the likes of Jason Segel, Cobie Smulders, Alyson Hannigan, Josh Radnor and Neil Patrick Harris?