Johnson is calling on the players to "show why they are at this club" and lift Blues out of trouble, starting with the home encounter with Bolton.
Alex McLeish's side have taken only one point from three games since their shock Wembley triumph over Arsenal and have been beaten by fellow strugglers West Brom and Wigan. In addition they lost 3-2 to Bolton in the quarter-finals of the FA Cup at St Andrew's.
But Johnson insisted: "The League Cup final took it out of us for a week maybe and you might expect a reaction the following game.
"But certainly not four games after that would you expect it. It's not good enough. We are a good bunch and it does hurt us to see where we are in the league, certainly after last season (finishing ninth) and now winning the Carling Cup.
"We have talked amongst ourselves about it. We all know we are down there and we need to step things up. People have got to start stepping up to the plate and showing why they are at this club."
Source: PA
Source: PA