Jarryd Hayne has announced his retirement from the NFL.

Hayne had a disappointing rookie season with the San Francisco 49ers but he insisted on continuing to work on his game this offseason.

Hayne is one of Australia's best rugby players.

"I am retiring from the NFL because the Fiji Rugby Sevens team reached out to me about the opportunity to join the team for the upcoming Olympics, and I simply could not pass that chance up," he said. "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.

"The 49ers organization has been incredibly supportive throughout my journey and I cannot thank them and the support staff enough. I am especially grateful to the strength and conditioning coaches, trainers and medical staff, equipment guys, public relations crew, chefs, logistics, and merchandise staff for their countless hours helping me in many different ways, so I could focus on football. Thank you to the fans from down under, as well as those around the world, who stood behind me and supported me along this amazing journey. I also want to thank the boys, especially my running back brothers, for their help and support in my transition to the NFL. I wish the team nothing but the best for the upcoming season.

"Last but not least, I would like to thank the 49ers Faithful for your unwavering support. From day one you have always been in my corner and I can't thank you enough for the love you've shown for the kid from down under. Signing off, your mate, number 38."

Hayne had 17 rushing attempts for 52 yards and eight punt returns for 76 yards.

"We would like to thank Jarryd for his contributions to the San Francisco 49ers organization and our community over the last year," general manager Trent Baalke said in a statement. "Jarryd is a tremendous example of what can happen when you commit to a goal and do everything in your power to make it a reality. He earned the right to wear a 49ers uniform and compete alongside the best in the game. We fully support Jarryd's decision to pursue another dream - representing the Fiji Rugby Sevens team in this summer's Olympic games. We look forward to watching him in Rio and wish him continued success."