Having always been an assistant during a career lasting over a decade, the 48-year-old Scot now has full responsibility for his own decisions.
He knows that means he will have to adapt the approach that served him well under spells with Jose Mourinho, the late Sir Bobby Robson and, most recently, Kenny Dalglish.
"I think I will need to be a bit more selfish now. I'm a head coach – I'll have to be very clear with my ideas," said Clarke, whose first competitive match in charge will be at home to his previous employers, Liverpool.
"I will also have to be a bit more ruthless.
"When you're the assistant, you can be nice to almost everybody.
"But as a head coach, although you want to be nice to everybody, at the end of the day you can only pick 11 players plus seven substitutes.
"There is always going to be a number of players who are not particularly happy that they're not in the team for whatever reason.
"That's something I'll have to deal with – but it's something I'm comfortable with and ready for."
Clarke has already started laying plans for the transfer market while also trying to tie up players left by Roy Hodgson.
He said: "I've been looking at the squad and deciding where we need to strengthen and what we need to do to improve.
"It's been very productive. I've met a lot of good people that have made me feel welcome. It feels great to be here.
"This is a really well-established club. The board have also helped make me feel really at home. From the moment I got here, I knew this was the right club for me."