First it was Andrew Bogut and now it is Jarryd Hayne.

San Francisco sports teams are making a habit of draping their Australian players in secrecy, lies and garbled messages, hoping to use their deception and tricks to keep opponents on the back foot.

Three months ago Golden State Warriors' head coach Steve Kerr looked reporters in the eyes at two separate press conferences and told them his 213cm-Melbourne centre Bogut would be in the starting line-up for game four of the NBA Finals.

"I lied," Kerr would later confess.

Kerr left Bogut on the bench and with the smaller, faster line-up defeated the Cleveland Cavaliers, evened the series 2-2 and went on to claim the NBA Championship.

It was a master move.

In recent days, to a similar room of reporters just 30 minutes drive down the 880 Freeway, San Francisco 49ers head coach Jim Tomsula was being unashamedly evasive about Hayne.

Tomsula and his staff have not confirmed publicly if Hayne, the former Parramatta Eel, will play or not in the 49ers' opening NFL regular season game against the Minnesota Vikings on Monday (Tuesday AEST).

But the coach has set off smoke screens and, interestingly, has been talking down his Australian recruit in the lead-up to the Vikings game.

One of the smoke screens was telling reporters the players have been informed if they will play the Vikings.

However, Hayne, while talking to the Nine network's Today show on Monday AEST, said he still did not know if he was suiting up - despite the game being just a day away.

"I still have to get the green light," Hayne said.

"I don't know if I'm playing at the moment."