The 29-year-old last appeared in an NFL game in 2013, as a member of the Minnesota Vikings. He played two seasons with the Vikings before being released last September.
Simpson spent the first four years of his career with the Cincinnati Bengals after being drafted in the second round in 2008. He made 18 starts for the Bengals during his time there and 18 starts for the Vikings over two seasons.
For his career, Simpson has 2,004 receiving yards, eight receiving touchdowns and a 13.8 yards per catch average.
In 2013, Simpson had a career-high 726 receiving yards on 48 catches.
- Molly Geary