Spurs host Frank's former team on Saturday afternoon struggling for form at home.
And the Dane accepts criticism from fans for the way he consistently changes his XI.
He said, "I think it's fair. I've got an idea of quite a few positions. Also, there's competition so it's not that easy all the time to say, 'OK, it's just those 11' because you need more than 11 players.
"But normally you see most teams when they are finding their strongest team it will be those nine players all the time and maybe change two. Or maybe sometimes it's 10."
Frank also insisted: "It's a combination with the amount of games and that rotation.
"Definitely for the rest of the season if we do well in the Champions League there will be rotations, but it will be closer and closer until you see the main nine or 10 players that we go with."