Robert had looked to be on his way to the Reebok Stadium from Newcastle United earlier this week, only for it to be announced that the Frenchman is now holding talks with Pompey, a club who had been linked previously.
Perrin has admitted that the former French international is on his list of possible recruits but fears Bolton's offer of European football could prove to be a deciding factor.
"I hope to be able to change his mind, although we have other propositions. I know Bolton can offer him the lure of European football next season but we will see what he wants." said Perrin