"Anyone who's watched me and watched the open workouts knows that we've been working on the left hooks, that the left hook will work and the left hook will finish Carl Froch," the Londoner told a news conference.
"It's a shot that Carl's always been vulnerable to. He doesn't cover his chin and the left hook will put him to sleep."
Froch, the defending champion from Nottingham, looked unperturbed and predicted Groves would not see out the fight.
"I'm convinced George Groves won't hear the final bell because I know what I need to do and I know how to do it," said the Briton, who has 32 wins (23 by knockout) from 34 fights with two defeats.
"I have prepared for this fight like no other before. I'm in unbelievable shape and I'm just really looking forward to doing the job on Saturday night and defending my two world titles successfully."
The fight is the first staged at the new national stadium in North London, with organisers talking of a sellout 80,000 strong crowd - more than any post-World War Two bout in Britain.
"When we started this journey we called (it) the biggest fight in British boxing history," said promoter Eddie Hearn. "I think it's got even bigger than that."
The two Britons first clashed at the Manchester Arena in November last year when Groves, 26 years old and with 19 wins and one defeat from 20 fights, was controversially stopped by 36-year-old Froch in the ninth of 12 scheduled rounds.
Groves had floored Nottingham-based Froch in the opening round and was ahead on the judges' cards when referee Howard Foster stepped in.
"This couldn't be more perfect," said Groves of the re-match. "I'm going to become world champion, in London, in front of so many people.
"After I beat Carl on Saturday, I'll be able to put it to bed but right now I'm still sore. I've been robbed and the finish was unjust because I was clearly winning and had it taken away from me," he added.
- Sports & Recreation
- Carl Froch
- George Groves