The PS3 to PS4 game upgrade process will work from retail copies of PS3 games, Sony Computer Entertainment UK chief Fergal Gara has confirmed to VideoGamer.com.

The upgrade path was announced yesterday but specific details on how it will work weren't forthcoming.

"It may work in several different ways, but I believe it will work from disc to digital, so you can buy the PS3 disc and then access the PS4 digital file," Gara told VideoGamer.com.

He added: "Therefore if you've bought into say Call of Duty Ghosts prior to the launch of PS4 you can buy into it and start playing it immediately on PS3, and then you can for a premium trade up to the PS4 version."

Gara added that this upgrade program is "for the gamer, we're here for the gamer... [so that] they don't face that conundrum on release day: 'Do I hold off or do I pay twice?'"

The SCE UK boss said that you can expect even more details on the upgrade program shortly.

This morning Activision announced that the upgrade from the PS3 version of Call of Duty: Ghosts to the PS4 version will cost a suggested £10.

PS4 will launch in the UK on November 29 priced £349.