NBA commissioner Adam Silver, in a conference call with players Friday night, said he is willing to wait until June before deciding on a firm plan to resume the season while raising the likelihood of two fan-less sites for the playoffs. According to a source on the call, Silver was “forthcoming and genuine in expressing the difficultly to plan in light of the uncertainty.’’ However, the source added Silver “informed the league’s desire to resume the season, but only if absolutely safe for all.’’