The Teessiders slipped to a sixth npower Championship reverse in seven games as they were trounced 4-1 at Crystal Palace on Saturday, a sequence upon which they are determined to improve, starting at Burnley on Tuesday night.
Friend told the club's official website: "You run it over and over again in your head and just hope you get a chance to put it right when you have another game.
"It was six hours back from Palace, but it wasn't just on that journey that I was thinking about the result. It's when you go to bed at night and on Sunday.
"You don't really stop thinking about it until you start preparing for the next game.
"The only way you can get out of it is to roll your sleeves up and say enough is enough. It doesn't do anyone any good to keep your head down for too long."