49ers running back Jarryd Hayne retires from NFL

Former Australian Rugby League star Jarryd Hayne's NFL experiment is over, as he announced his retirement Sunday from the San Francisco 49ers in order to join the Fiji Rugby Sevens team for the Rio Olympics.

Hayne says: "I simply could not pass that chance up. The Olympics has been something I have admired since I was a little boy, and it is an opportunity I feel very similar to me joining the NFL."

A 6-foot-2, 220-pound running back, the 28-year-old Hayne was a surprise to make the initial 53-man roster out of training camp last year with San Francisco.

Playing eight games with one start for the 5-11 Niners, he had 17 carries for 52 yards and six catches for 27 yards while also returning eight punts for 76 yards.

He joined San Francisco as an undrafted free agent on March 3, 2015.