The upcoming revival of the 1980/’90s sitcom, “Roseanne,” may have a few roadblocks in the casting department. While almost all of the original stars from the original ABC series have signed on to the long-awaited eight-episode reboot (even both actresses who played Becky Conner), there has been one glaring omission. Johnny Galecki, who played David Healy, Darlene Conners’ (Sara Gilbert) longtime love and baby daddy, has not revealed if he will be participating in the upcoming 10th season revival of the series.

Why Johnny Galecki might not return to “Roseanne’

Galecki has a pretty good reason for avoiding the “Roseanne” revival. He has a full-time job on the megahit sitcom “The Big Bang Theory,” which airs on rival network CBS. In addition, Galecki is slated to star in a new series, "By the Book,” which recently nabbed a full series order on CBS, according to Variety. In addition, Galecki recently lost his California ranch to a massive fire and may just be too busy to head back to his roots with "Roseanne,” despite the fact that he still maintains a close friendship with several of his former co-stars, including Gilbert.

Still, TV Line reports that Johnny’s character, David Healy, will “have a strong presence” on the ABC reboot.

The site reveals that executive producers Roseanne Barr, Sara Gilbert, Whitney Cummings, and Bruce Helford are on the hunt for two young actors to portray the children of Darlene and David. In the final season of the original “Roseanne” series, Gilbert and Galecki’s characters welcomed a baby daughter they named Harris. The reboot will now introduce the couple’s son.

If Galecki doesn’t return for the “Roseanne” reboot, that could put Darlene’s character in a variety of situations, none of them good. The show could make her a widow, or David could be painted as an absentee dad. Best case scenario: Darlene and David got divorced and he moved far away from Lanford, Illinois.

A somber situation will need to be addressed

Even if Johnny Galecki does return to “Roseanne” (a move that would be a major coup for the network and for fans of the show), the revived series will be forced to address a much more somber situation. Glenn Quinn, who played Mark Healy (David’s brother and Becky Conner’s husband) on the original incarnation of “Roseanne,” died of a drug overdose in 2002. The loss of Mark Healy will have to be addressed in some way on the “Roseanne” revival, and that will be sad enough for fans.

Roseanne” returns to ABC for eight episodes in Spring 2018.