Sanchez was suspended four games for a positive performance-enhancing drug test, the National Football League announced on Friday.
Sanchez was the Jets first-round draft pick in 2009 and took the team to two consecutive AFC Championships but has been relegated to a backup since leaving NY after the 2012 season. He is eligible to participate in offseason and preseason practices and games.
In it, Sanchez says he "was blindsided by the news and I want to say unequivocally that I have never cheated or attempted to gain a competitive advantage by using a banned performance enhancing substance".
"During the past nine years as an National Football League player, I have been subject to 73 drug tests - and all but one have been clean".
Sanchez blamed the positive test on an "unknowing supplement contamination". He has played in a game since the 2016 campaign with the Cowboys making a pair of appearances where he completed 10 of 18 passes for 93 yards with a pair of interceptions while holding a 30.3 passer rating.
Sanchez was drafted fifth overall by the Jets in the 2009 draft. He was a starter for NY from 2009-12 and established career bests of 3,474 yards and 26 touchdowns in 2011.
The 31-year-old has already responded to the news via social media stating that this had taken him by complete surprise as he had been tested 73 times throughout his career and had not failed once before this test. He was third on the Chicago Bears' depth chart last season and did not see any regular season action.