Woodgate has only featured in three games over the last year and is currently struggling to overcome a persistent groin problem, despite jetting around the world for specialist treatment.
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With the Premier League introducing a limit of 25-man squads this year, Redknapp admits time is almost up for the 29-year-old.
"Woody's nowhere near right now. I couldn't put him in my 25. It's just impossible at the moment," Redknapp told BBC Sport.
The new rule means Premier League clubs have to name a squad of 25 senior players by August 31, with only youth-team players - under the age of 21 - allowed to supplement the squad until the transfer window re-opens in January.
And Woodgate now has to prove his fitness by the end of August or risk being left on the sidelines for another three months.
"It must be really hard for Woody at the moment because he's nowhere near kicking a ball," added Redknapp. "He has been out for nearly a year, been in America and Australia but he's still nowhere near.
"You can't have somebody in who's never going to play, if he's not going to be fit.
"He's got to really prove that between now and the start of the season. To have any chance he's got to be playing, otherwise you couldn't possibly have him in the 25. Not at the moment.
"He's a long way off now. We'll see how we go in January."
Redknapp already has concerns over Ledley King's chronic knee injury and he expects add a new defender to bolster his squad before the end of the window.
"I think if you are clever there are loans out there that for clubs like us would be interesting."
By James Martini
