Mets placed LHP Johan Santana on the 15-day disabled list with a sprained right ankle. Santana will miss a minimum of two starts, meaning Matt Harvey could be promoted if an extended absence is required. Jeremy Hefner is tentatively scheduled to replace Santana in the starting rotation Wednesday against the Nationals, though the Mets have yet to make an official announcement. The ankle injury reportedly forced Santana to rely more on his arm for delivery, so he's also dealing with minor shoulder fatigue.