A Dirk Kuyt double earned the hosts a 2-0 win against an under-par Spurs side at Anfield on Wednesday night.
"We came here in good form but really I was disappointed with us tonight," Redknapp told Sky Sports after the match.
"We had a great opportunity and we didn't take it. We had some players who were below par tonight.
"We got off to a bad start. They worked hard, pressed hard and played with great enthusiasm.
"You never get an easy game here. They responded to the crowd and they deserved their win.
"We had a decent spell at the start of the second half when we started to hit Crouchy because we couldn't play through midfield.
"Liverpool had key players missing but we missed having an outlet like Aaron Lennon.
"We lacked that bit of spark and pace."