Kane came into the tournament on the back of an impressive season for Tottenham Hotspurs but he is yet to hit the ground running.
Kane has drawn blanks in both England games against Croatia and Scotland, and has uncharacteristically looked out of sorts.
The 27-year-old, who won the golden boot at the last World Cup, is yet to record a shot on target and has been hauled off in both games.
"Gareth [Southgate] is within his rights to make the changes he thinks are best for the team," Kane told The Guardian when asked for his reaction to being replaced in both of England's games so far.
"What we've learned over past tournaments is about trying to peak at the right time. The best time to be peaking is in the knockout stages and hopefully kick on from there.
"Maybe in Russia there were times, towards the quarter and semi-final, when I wasn't as sharp as I wanted to be. In the end we didn't get to where we wanted to go, maybe partly for that reason.
"It's about managing the squad, making sure everyone is feeling as fit and sharp as possible. In my case, it was a tough couple of games and it's about making sure I'm right for the rest of them.
"I didn't have any issues. I didn't feel physically I wasn't up to it. I felt going into those games as good as I've felt all season, if I'm honest."
"All my focus is on how I can help this team and how we can be successful in this tournament.
"I understand from a media point of view there is speculation but I am fully focused on the job here."