Fantasy Upside
Similar to last year, Mostert is being undervalued in the draft season because there's just no way a 32-year-old can do it again! Except maybe he can? At RB27 on Underdog, he doesn't even have to finish as RB3 again this year to exceed expectations. He just has to maintain some level of efficiency and not concede the majority of the goal-line work that led to him scoring 21 touchdowns. Mostert still has to remain healthy, but the situation hasn't really changed enough for him to be going this low.
Fantasy Downside
The story you tell yourself if you're looking to fade is that age, injuries, or both catch up to Mostert and Achane takes over as the lead back in a 50/40/10 split with Jaylen Wright and concedes some of the goal line work. It seems more likely he concedes the lead-back role than the goal line, but injuries or age could derail it.
2024 Bottom Line
The bottom line on Mostert is that as long as he maintains the goal-line role he'll still be fantasy-viable every week. Going as the RB27, he's a strong buy in best ball and half-point PPR redraft leagues.