Murphy, speaking to the club's official website, said: "If we don't get the right result against Middlesbrough that result won't be relevant. We have to build on the feelgood factor that beating United creates."
"I know the supporters haven't had a lot to shout about this season but at least we've given them some hope about getting into the Champions League.
"There's no point us winning that game and not taking any impetus from it. Newcastle and Aston Villa are going to keep pushing us so we've got to win the next three games."