Quinn joined the ABC comedy in Season 3 as Mark Healy, Becky Conner's (Lecy Goranson) boyfriend. He recurred throughout the rest of Roseanne's original nine-season run, which saw Mark and Becky eventually getting married. In 2002, five years after Roseanne ended, Quinn died of an accidental overdose at the age of 32.
The Roseanne revival wrote Quinn's death into the new season, although they haven't revealed how Mark died. Tuesday's episode focused on Becky's struggles with infertility, with Becky learning that there's almost no chance of her being able to have a biological child. In the wake of learning this, Becky tells Darlene (Sara Gilbert) that she and Mark had tried to have kids before his death and that she has never met anyone since that she'd consider having a child with. Darlene tells Becky that it won't be a betrayal to Mark if Becky allows herself to move on.
The episode then closed with a tribute to Quinn, dedicating the episode to his memory.
His co-star Michael Fishman also honored the late actor on Twitter, noting that "As long as [Roseanne] is on Glenn Quinn is part of it."