FIFA want extended squad lists submitted by May 11 before the final 26-man squads are whittled down.
Clarke initially joked: "It’s a FIFA requirement that you put in a squad, I think it’s about 55 names. And I’m definitely No 55!
"But I’ll find 55, for sure. I’ll find 55 names. On the back of that, obviously your 26 will come from that group. It’s just a FIFA requirement that we have to do.
‘There can be late additions too. But hopeful I don’t forget anybody. We’ll work on it. We’ve got Steven Naismith (assistant coach) as well and I think he wants another cap."
Asked about phoning the 29 players who won’t make the final cut, Clarke added: "No, not from the 55. I won’t be doing that. I won’t be going round every single name.
"I would imagine across the month of May, when I’m speaking to people and possibly giving them the news that they haven’t made the squad, I’ll be telling them that they have to be ready.
"I think right up to the first game, you can change players. And into the tournament, you can only change the goalkeeper.
"We will have a few players on standby that they will know. I won’t make public a standby list. I’ll just name the 26."