Gerrard endured an injury-hit campaign last season – making just six appearances after the return of Kenny Dalglish as manager at Anfield.
The 31-year-old underwent surgery and Redknapp says he is critical to the club's hopes of re-establishing themselves as trophy contenders next season.
“I hope he is back to full fitness next year - he is Superman," Redknapp told Liverpoolfc.tv.
"Hopefully he can come back to full fitness - that's the key. He's had surgery - I spoke to him and he said he feels great and really strong.
"I think it's really exciting times. With Kenny back there, and Luis Suarez - I love watching him play. It's exciting times for Liverpool and I hope we can get back certainly into Champions League football. With Kenny, I believe that can happen."
Redknapp was signed by Dalglish as a youngster and went on to make over 300 appearances for Liverpool, but never won the Premier League – a trophy that has also continued to elude Steven Gerrard, though Redknapp thinks they will be in contention next season.
“It was different class to see Kenny back," said the 37-year-old.
"He signed me as a 17-year-old. All the fans have responded to it. When I've been to Anfield the atmosphere has been so good because he's there, he has that magnetism. People love him and love watching his teams play.
"Next year will be the most open league title in years. You look at it and with one or two new players - and Kenny will have identified those - I don't think Liverpool will be far away, and I'd love to see that."