Brazil goalkeeper Cesar has been linked with a season-long loan to Napoli as he aims to safeguard his international place ahead of next summer's World Cup finals.
And newspaper reports on Tuesday claimed Hull manager Steve Bruce wants playmaker Taarabt on similar terms.
But Redknapp has told interested clubs to make a cash offer or forget about signing either player.
He said of Cesar: "I can't see the sense in loaning him for a year. He's got three years left on his contract, he's just played for Brazil in the Confederations Cup and been absolutely fantastic.
"I think he's a goalkeeper for any team in the world he's that good, so to loan him out for a year and then have him back is absolutely pointless.
"What's the point in loaning him for a year then getting him back on massive wages for another two years? He's in his prime at the moment, I'm sure he's wanted by lots of clubs around the world.
"If he wants to leave, we sell him. Napoli are not short of money, they're just selling Cavani for £54million, so if they want him surely they've got to come and do a deal.
"We have to do a deal that suits the football club and not deals that suit agents and other people."
On Taarabt, he said: "There's talk about him going to Hull on loan. What's the good in that? If he wants to go, let somebody come and pay the money for him.
"If nobody wants to buy him, he stays here and he gets fit. He has to show he's a good player and help to get QPR back in the Premier League.
"If he really wants to go that bad and someone wants him - pick up the phone, make an offer and we'll do some business. No problem."