Ahead of this weekend’s FA Cup semi-final against Chelsea, Redknapp made five changes from the draw with Sunderland on Saturday and saw his side slip to a 2-1 defeat at White Hart Lane.
And Roberts says Redknapp must stop tinkering with his line-up if Spurs are to cling on to a Champions League qualifying spot.
“There is a big cup tie but the Champions League is more important to Spurs and Spurs fans,” the former Tottenham star told the Alan Brazil Sports Breakfast show.
“You have to play your better players. You can’t say you are saving them for Sunday when it is a week away. It is not two days. When we played you used to play your best team and if one person got injured you would change it.
“You can’t keep changing the team,” he added. “They brought [William] Gallas in against Chelsea last week and he was fantastic and then they leave him out yesterday to save him for Sunday. You can’t keep doing that.
“You have to get a settled defence, a settled line-up, and the players will react to that. Yesterday the lad from Blackburn, [Ryan] Nelsen, came on for [Younes] Kaboul in the second half and you can’t keep doing this. You can’t keep changing your team about.”