sounds like he was running routes with QB's in practice, no contact, and tore his Achilles.
Probably more fantasy football interest on here than real football, but...
& #8207;Verified account @MikeKlis
13m13 minutes ago
Terrible news: Broncos WR Emmanuel Sanders has torn Achilles, per source. Happened right in front of me at practice. He was cutting in on shallow in-route against air when he went down. #9sports
& #8207;Verified account @AdamSchefter
3m3 minutes ago
Broncos’ WR Emmanuel Sanders was running routes against air for the QBs to get throws in. Uncovered, on a short route, Sanders went down. It looked like he knew right away. He took his helmet off immediately, rolled it away from him and trainers checked his left ankle/lower leg.