Redknapp is keen to trim his squad as he looks to make changes over the summer to plot a fresh bid to finish in the top four next season, and he has allowed a number of those players the chance to go out on loan to secure suitors.
However, while Jamie O'Hara has established himself in the first-team at Wolves, Keane, Giovani and David Bentley have proved less successful in their spells at West Ham, Racing Santander and Birmingham respectively.
"Jamie has done well at Wolves, but the others haven't done so well," Redknapp said. "That could make it harder for us to sell them but we need to trim the squad.
"What we need to do is sell five or six players and bring in two or three top-quality players so we can start challenging the top four teams every year."
One player who should have no problem finding a new club is Niko Kranjcar, with Redknapp having reluctantly accepted that the Croatia midfielder will move on after failing to secure regular first-team football.
Redknapp, though, has rubbished suggestions Aaron Lennon could also be on the way out. There have been reports of a disagreement with the England winger after he pulled out of Spurs' Champions League clash at Real Madrid with illness just minutes before the kick-off.
"I want Aaron to stay," Redknapp said. "He's never had a bust-up with me - that's absolute rubbish.
"I have never, ever crossed words with the boy. How do they dream these things up? I have never had an argument with him."