With regular co-captains Dylan Hartley and Owen Farrell picked as replacements, flyhalf Ford and lock Itoje come into leadership roles as England look to get back to winning ways after an agonising 16-15 defeat by New Zealand last weekend.
"Fortunately I have vice-captain next to my name this week but not much changes for me," Itoje told Sky Sports on Friday.
"I'm still planning to go out there and play my game and support Ford when I can and lead the boys as well as I can."
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Itoje said the players were working on their lineouts after losing five on their own throw during the All Blacks defeat.
"I think it's important to understand the reasons why that happened," he said. "We didn't adapt well enough to the conditions and to what the All Blacks were doing in the second half.
"Japan have a very good lineout, they are a very well-drilled side and they have a lot of good jumpers so it's going to be interesting again."
Although Japan were thrashed 69-31 by a second-string New Zealand in their last match, Itoje said England are taking nothing for granted and training at a high intensity to mimic shorter preparation time for matches at the World Cup next year.
"Probably from the outside you think that because we're playing a team lower ranked than us, it's an opportunity to switch off or turn it down a little bit, but that's definitely not the case," he added.
"We always prepare for the next game and we are fortunate enough to have some insights into Japan through our two coaches - Eddie and Steve (Borthwick) - who have coached them for a number of years. Hopefully, we will give a good performance on the weekend."
(Reporting by Hardik Vyas in Bengaluru. Editing by Patrick Johnston)
