Murphy, 23, joined the club in the close season from Wakefield, and was drafted in to the side to face London on Sunday when Eden fell ill.
Skipper Kevin Brown said: “Aaron was great he got given his chance and he took it, his general game play was very solid and he made a fantastic save tackle on what would have been a certain try, we definitely have some competition for places.”
Murphy produced a couple of important try-saving tackles in the 30-16 win at Twickenham Stoop, and coach Nathan Brown was also impressed.
He said: “To be honest, I think Aaron should feel encouraged with the way he went on his first run-out for us. He only found out in the morning he would be playing, when Greg Eden had been taken ill overnight, he took his chance very well.”
Murphy made his Super League debut for Wakefield in a 22-20 win over Hull in March 2008, and went on to score 15 tries in 64 appearances for the Wildcats.