Hayne was in PR mode at a press conference in London today, where he said the Olympics was "something I have admired since I was a little boy, and it is an opportunity I feel very similar to me joining the NFL".
He didn't want to speak about his career beyond the Olympics, when facing the media outside Chelsea's Stamford Bridge ground. He said the Olympic opportunity was something "money can't buy".
Meanwhile ESPN NFL host Trey Wingo said it was amazing that Hayne made it on to the field for the 49ers.
But new coach Chip Kelly liked smaller running backs, and Hayne's only future was probably in special teams anyway. Wingo had no idea whether the team had given Hayne an indication he was on the outer, so prompting him to make the shock decision to quit.
Wingo told Radio Sport's The Crowd Goes Wild Breakfast: "A lot of things went well for Jarryd...to come over with such a little football background and make the team last year was an amazing accomplishment.
"The skill set sometimes doesn't translate. Jarryd is a really strong powerful runner but in the NFL you want to avoid as many of those hits as possible. He never really acclimated his running style and he made the right choice in the end.
"The long term prospects weren't that great for him - most running backs past 30 don't do that well in the NFL. If it wasn't going to work now...he's 28 and had the chance to get into the Olympics. What he achieved spoke for his athletic ability, grit and determination. No question."