The 32-year-old frontman has not even been given a squad number, but if no interest is shown from a potential buyer, then Roberts could well be able to fight to keep his place at the club.
"I have decided he is available for transfer and if I play him, I could risk him getting injured," Allardyce told the Daily Star. "That would be the wrong thing to do.
"We have made a decision between us and we will see what develops in the next eight days.
"If he doesn't go anywhere, then he doesn't go anywhere.
"It is about being here and knuckling down and getting on with it, if that is the case.
"He would like to move on and if that is the case, we could use what money we get in to maybe top up someone else we haven't targeted at the moment."