In an open letter published Saturday, NFL Players Association president JC Tretter called for the NFL to take several steps to increase safety measures for players, including the banning of slit film turf.
Tretter wrote that of the three types of turf used at NFL stadiums—slit film, monofilament and dual fiber—slit film is statistically proven to cause more non-contact injuries, lower extremity injuries and foot and ankle injuries, in addition to causing players to miss more time because of injuries.
Tretter added that the NFL and its experts acknowledge that the data is correct, but, "The NFL has not only refused to mandate this change immediately, but they have also refused to commit to mandating a change away from slit film in the future at all.