Joshua will return to the ring for the first time in seven months as he looks to bounce back from consecutive defeats to Ukraine's Oleksandr Usyk.
Franklin – his opponent – has a 21-1 record and lost his most recent bout against former world title challenger Dillian Whyte.
Joshua has moved to Dallas, Texas for this fight camp as he links up with renowned trainer Derrick James, with the heavyweight looking to get back to basics as he chases a winning formula.
He said: "His message has been pretty simple… to go back to basics.
"The best athletes all do the basics well. In my last fight, I feel I maybe moved away from that a little bit.
"So, much of the in-camp training for the Jermaine Franklin fight at the O2 [Arena] on Saturday has been about stripping it down to the bare bones, getting my jab right, my defence, all the fundamentals of boxing.
"This is just the next chapter in my story but it also feels like the start of a long run, one I'm confident will also prove to be a long run of success.
"I see myself boxing for another three or four years and it feels like there are a lot of big nights ahead."
The 33-year-old's fight in London on Saturday will be his first without a world title involved since April 2016, but Joshua recognised the importance of the bout and the influence of new coach James.
Speaking at a press conference on Wednesday, he said: "This is massive! I've put in the work, I still dream big so I'm gonna go out there and make sure I get the job done.
"The goal is to take him out.
"Derick is up there with one of the best people I've ever spoken to about boxing.
"I appreciate his time and the fact that he took me one, he's a well sought after coach and I'm looking forward to showing him that he hasn't wasted his time by taking on this project."