Redknapp dismissed claims a deal had already been struck to sell the player for 40 million euros, as was reported in Spain on Friday.
"I don't know anything about (that story)," Redknapp said.
"I wouldn't think there is the slightest bit of truth in that. Not a chance, I wouldn't have thought.
"You have got to keep your best players. If you don't then where are you going? You can forget about Champions League football in the future if you sell them and they [Bale and Modric] are two of them."