Stanton (calf) has started running on an Alter-G anti-gravity treadmill, Bryan Hoch of MLB.com reports.
According to manager Aaron Boone, Stanton got up to six miles per hour on the treadmill, toeing the line between a brisk jog and a light run. While the increased activity is a good sign that Stanton's right calf strain is improving, the slugger remains doubtful to be ready for Opening Day.