McCarthy confirmed Johnson will play and lead the side against Manchester United at Old Trafford after his replacement, Jody Craddock, was ruled out with a hamstring injury suffered during the 2-1 win over Sunderland. Johnson made the £5million switch from Birmingham in the summer but has been below his best in recent weeks. Now he has the chance to demonstrate his credentials against a United side looking to bounce back from their Champions League exit at the hands of Basle in midweek. McCarthy said: "Johnson went out of the side because he was not as good as he should have been. "I had to look to change things and Jody did well last weekend before getting his hamstring problem. "But I had a great response from the Tuesday onwards before the game because Roger knew from then (that he was dropped). "What was really nice was that no one knew until kick-off. That tells me a lot about him. There was no social networking going on and people finding out. "The response I got from then on was brilliant. He had a great week training and, when he came on (for Craddock), he turned it around for us. "He had a great header from under the crossbar when Wes Brown was all over him. I had a really good response and that's what I would expect from him. "I need another one now tomorrow at Old Trafford and he has to be at his best like in the first three games of the season when he was terrific." McCarthy believes it will only be a matter of time before Wayne Rooney - without a goal in open play since September 21 - starts scoring again and knows his side have to be at their best against United. He said: "It's a bit like going to Chelsea a few weeks ago when everyone was saying 'it's a great time to play Chelsea'. "When is it a great time to go and play Manchester United at Old Trafford or Chelsea at their place? "I just don't see that. We have to go there and play well and take care of our performance and we didn't do that at Chelsea. "We've got to play well and, if we allow Wayne Rooney to play and get chances, he will score, because he's a top player. "It is class, it is permanent and it will come back. He might be out of sorts from time to time but he is a class player." McCarthy is hoping his own in-form striker Steven Fletcher can cause United problems after scoring 15 times in his last 22 Premier League appearances. He said: "We have got a man in form in Fletch. I am delighted with that and he is delighted to be back fit. "We are all happy to have him out on the pitch because he has missed a lot of football. "He has been prolific and that is what I thought I was signing, well that's what I knew I was signing. "That's why he was my marquee signing the year I signed him and whenever he has been fully fit, he has tops for us." Midfielder Karl Henry will return after serving a one-match suspension for incurring five yellow cards this season.
