Johnson is sure his team-mates can cope with the pressure of topping the table and end a 24-year wait for the league title.
"Any team who is top of the league at this stage deserves to be there," Johnson said. "This is a difficult league with a lot of tough games but I think we can stay there.
"This is a fantastic club. Everyone involved here loves it and wants to win the league badly. We want to get the club back where it should be.
"But being top now is only significant if we stay there. Forget the league table, just win at Upton Park (against West Ham on Sunday).
"Playing in the best league in the world, the hardest thing is to go game by game.
"Every day you've got your mates texting you and you see on the news how close you are. But everyone here is professional. Every time we come here we have a job to do.
"We have to make sure we win our next game. We all know what's expected of us and we're all confident."