Woodgate, 30, made just three appearances last season as he was hampered by a groin injury and the centre-back will miss Spurs' pre-season tour of the United States to work on his own personal fitness programme.
Under new Premier League rules, clubs must name a 25-man squad for the season and even if Woodgate is fit enough to be selected he is not guaranteed a starting spot with the likes of Michael Dawson, Ledley King, Sebastien Bassong and Younes Kaboul all battling for places.
To complicate matters, the former Real Madrid and England defender is out of contract at the end of the forthcoming season.
"It's make or break for Jonathan now," Redknapp told the Daily Telegraph. "He has got to come back and play. If he is not ready for the start of the season it will be difficult for him. When he gets his boots on and starts playing hopefully he will be all right.
"He is a fantastic player: one of the best centre-halves around. We just take it day by day with him and see how he progresses."