D-lineman Armond Armstead retires

New England Patriots defensive lineman Armond Armstead, a highly touted prospect who signed with the team in 2013 after an all-star season in the Canadian Football League, has announced his retirement.

Armstead, 23, was referred to as a top-3 player in the Patriots' defensive tackle rotation last year by coach Bill Belichick, but an infection before the start of 2013 training camp ultimately landed him on season-ending injured reserve. He never played a game with the team.

Armstead suffered a heart attack while at USC, where he played from 2008 to '10, and he later sued the school. His medical condition had led him to the CFL, where he starred for the Toronto Argonauts in 2012 before signing with the Patriots on Feb. 1, 2013.

Armstead was present for some of the Patriots' initial organized team activities this past May, but it was clear something had stalled his progress when he wasn't spotted for the final few weeks of OTAs.

Belichick was evasive on the topic at the time, but offered the following statement Wednesday: "It has been a pleasure being around Armond, as he gave us everything he could to play for us. Armond worked extremely hard since joining us last February. He's had a lot of adversity personally that he's had to deal with -- unusual compared to most other players -- but he's always had a great attitude, worked hard, and really did everything we asked him to do. While it is unfortunate he will not be able to play football, Armond is an outstanding young man who has a very bright future in whatever path he chooses."

The retirement likely didn't come as a surprise to the Patriots, who had made a competitive bid to sign free-agent defensive tackle Kevin Williams in June. Williams said he turned down more money from the Patriots to sign with the Seattle Seahawks.