"There must be something going on behind the scenes because it's quite a unique selection.
"You talk to anyone who knows anything about sevens, you're looking at about a period of three to six months to be ready to play at the top class level. You can't just walk in. It doesn't' matter if you're the best runner in the NFL, you've got to be able to play sevens.
"Certainly, his performance in London suggests he's going to be struggling to make that team."
Hayne struggled to make an impact in his sevens debut and struggled to read the play.
He was also limited to playing minimal minutes at the back-end of Fiji's matches.
It's not about game time, it's about going out there and doing a job for the team," he said after the London event.
"It's all hard, continuous, I got caught in the ruck a couple of times too.
"That was a good learning curve and when you're rucking and trying to ruck the ball obviously you exert a lot of energy.
"It's so much faster, it's a lot quicker, (I'm) still getting used to it. I'm just being a sponge and learning as much as I can."
Meanwhile, Jones has come under fire for directing a "rugby league slur" at former England rugby star Sam Burgess, who has returned to the South Sydney Rabbitohs in the NRL.
Jones sensationally said the 13-a-side rival code is "not a skilful game" while explaining why England Rugby's Burgess experiment failed.
"Burgess was a non-event in England's confused strategy at the World Cup but he would have been an excellent Test player if he'd had the will to stick at it," Jones said.
"Rugby league is not a skilful game, it's a game where you've got to hurt people.
"Tough guys like (former NRL star) Ben Te'o bring something extra to a squad, a bit of an intangible, plus he's done the hard yards in 50-odd games for (Irish club) Leinster."
