FLORHAM PARK, N.J. -- Former starting safety Antonio Allen, a valuable backup for the New York Jets because of his versatility, will miss the entire season after tearing an Achilles tendon Thursday in practice.
An MRI on Friday morning confirmed the injury.
Allen was waived with an injury designation, the team announced. It means he will be placed on the Jets' injured reserve list, assuming he clears waivers.
To fill Allen's roster spot, the Jets signed cornerback Keon Lyn.
"That was a tough break for him," coach Todd Bowles said of Allen. "He was having a good camp. The guy comes to work, he practices hard, he plays hard. A freak accident -- nobody touched him. He's just taking off on his foot and his Achilles goes. My heart goes out to him."
Allen was hurt on the final play of practice, a noncontact injury on a grass field. He came out of his stance on the snap of the ball and crumpled to the ground.
It's a major blow for Allen, who is entering the final year of his rookie contract.
A seventh-round pick in 2012, Allen worked his way into a prominent role. He was a safety for his first three seasons, but he was moved to cornerback last year because of injuries and a lack of depth. He wound up starting eight games. He played 495 defensive snaps, including 370 at corner, according to ESPN Stats & Information.
Allen has played in 38 games, with 2.5 sacks and one interception, which he returned for a touchdown. He's also a contributor on special teams.
The injury leaves only one experienced backup safety on the roster, Jaiquawn Jarrett, so the Jets likely will look into adding another player. The starters are Calvin Pryor and Marcus Gilchrist. Cornerback Darrin Walls got some work at safety in practice. He is seen as an "emergency" safety, Bowles said.