Mulder is a wildcard for this team and we all know it. Briscoe is a beast on the glass and solid defensively, but we desperately need someone who will allow Ulis and Murray to penetrate without allowing the third opposing defender to slide off his man (whoever is guarding Briscoe) and help.
It's allowing teams to play us man-to-man without having to defend Briscoe, making their schemes exponentially easier to develop and employ.