The 32-year-old French defender is available on a free transfer after being released by Arsenal at the end of last season.
"I like Gallas," Redknapp said. "I think he's a great free transfer. It is a possibility. His people hand rung up and we spoke about it.
"He is an experienced player. He has played at the top level, he won championships with Chelsea.
"You can go on for ever about the fact he played for Arsenal. He played for Chelsea as well. We put too much importance on that all the time.
"If he comes in and plays rubbish then the crowd will slaughter him. If he comes in and plays great they will love him. That is football."
Redknapp has made just one signing so far this summer, bringing in Brazil midfielder Sandro.
Fulham boss Mark Hughes is set to continue his pursuit of another City star, Craig Bellamy, with the former City manager insisting he can "bring the best" out of the controversial Welsh striker. (Guardian)
Stoke boss Tony Pulis has told Carlo Ancelotti to forget about signing Bosnian goalkeeper Asmir Begovic. (Mirror)
Radoslav Kovac's move to Stoke has hit a major snag, as current club West Ham have decided to hold onto the Czech midfielder. (Mirror)
Birmingham are close to sealing a 2m deal for Sunderland defender George McCartney, and are also in talks to bring Olympiakos's Matt Derbyshire back to the Premier League. (Mail)
Slovenian defender Branko Ilic has been given a trial at Blackpool, with the 27-year-old keen on a free transfer to the Premier League newcomers. Bolton defender Chris Basham, meanwhile, has completed his £500,000 move to Bloomfield Road. (Mail)
Wigan are mulling over a £500,000 bid for Orebro SK's Finnish striker Roni Porokara, who is eager to ply his trade in England. (Mail)
Meanwhile, wantaway midfielder Charles N'Zogbia stormed out of training yesterday, in an attempt to force through a move away from the DW Stadium. (Mirror)