Munster head coach Graham Rowntree has sprung a major surprise, with Conor Murray dropped from the matchday squad for Saturday's crucial Heineken Champions Cup Round 3 game against Northampton Saints (live on RTÉ2 and RTÉ Player).The 33-year-old has been left out for the visit of the Saints, with Craig Casey starting at scrum-half, while Paddy Patterson has been rewarded for his good form with a place on the bench.Murray had missed the province's opening Pool B game against Toulouse due to a groin injury which he suffered during the Autumn Nations Series, but returned to the starting shirt for the province's following two games against Northampton and Leinster.Patterson started the two most recent games against Ulster and the Lions, scoring a try both times, with Murray replacing him off the bench on each occasion.And the 24-year-old has pipped the province's longtime first-choice scrum-half this weekend, with Graham Rowntree opting for youth ahead of experience.Patterson has enjoyed a breakthrough season since stepping up from the academy to the senior squad this term, with the Dublin native playing nine times, scoring two tries, while he was also Player of the Match in November's famous win against a South Africa Select XV in Páirc Uí Chaoimh."Paddy's doing really well, he got man of the match that night, he's elusive, he's electric, he's exciting, he's very similar to Craig Casey, where he brings that energy," said former Munster out-half Ian Keatley on this week's RTÉ Rugby podcast.Speaking earlier in the week, Keatley suggested Patterson has earned his shot after some strong performances."You look at this weekend, you'd say Northampton are out of it, but it's a good opportunity to throw in one or two of those young