The 23-year-old, who made his debut for the Blades in Saturday's third-round FA Cup win at Oxford after signing for an undisclosed fee, revealed he turned down the chance to join Championship side Blackpool last year and that his former manager Stuart McCall, who spent two years as a player and coach at Bramall Lane, had helped make his mind up.
"It was always about finding the right club and when Sheffield United came along I knew it was the right club for me," said Murphy.
"The gaffer said it's a great move for me. If he had said it wasn't a great club, I don't think I'd be here. He means a lot to me, he's done a lot for my career, so I listen to his advice."
Murphy added: "There was obviously the Blackpool thing last January, which I didn't know anything about until 4pm on the last day (of the transfer window) and I didn't just want to go for the sake of it.
"We were pushing for Champions League (qualification) as well at Motherwell, so to get Champions League in the summer and to move now has worked out ideal.
"I can hopefully bring some goals. If I can score goals from midfield, or if the manager wants me to play up front, I can play there as well.
"If the manager wants me to play on the left, on the right, or up front, that's up to him, but I'm willing to play anywhere."