Glasgow Warriors head coach Gregor Townsend has urged Henry Pyrgos to rise to the challenge at scrum-half against Connacht in the RaboDirect PRO12 after Chris Cusiter was ruled out until December with a shoulder injury. Townsend saw his side pick up a first RaboDirect PRO12 win under his tenure last time out against defending champions Ospreys but will be seeking their first win at their new home, Scotstoun, on Friday. History is on the Warriors’ side, having triumphed at home to Connacht last season but Townsend was left to count the cost of his side’s victory in Swansea as 30-year-old Scotland international Cusiter was ruled out until the end of the year. Pyrgos, 23, has been selected for the clash to face Connacht but he will soon be challenged by new Fijian signing Nikola Matawalu, who arrives next week. And Townsend has called on Pyrgos to lay down at marker. “Obviously it is big blow when you see the type of injury sustained by Chris, especially when he was looking physically in the shape of his life,” Townsend told the Daily Record. “Henry did really well when he came on against the Ospreys. We know he is capable and Nikola will add competition.” And Townsend is in no doubt as to the challenge posed by Eric Elwood’s men. He told the Glasgow Warriors website: “Connacht are a battle-hardened, very proud unit whose defeat to tournament leaders Scarlets last weekend didn't reflect how well they performed in the game. “Our recent record against them underlines just how disciplined, aggressive and accurate a performance will be required to follow up our excellent win over Ospreys with another victory this weekend. “As a group, we are really energised by the opportunity to give our supporters a first win at Scotstoun, but are fully aware of what it will take to bring about a positive result.” As well as Pyrgos coming in for Cusiter, Townsend makes a further three changes with Sean Lamont replacing Tommy Seymour on the wing, while Moray Low starts at tighthead and Ryan Wilson returns at No.8. Connacht meanwhile, have scrum-half problems of their own as Frank Murphy has been ruled out for the majority of the season with a knee problem, joining Paul O’Donohoe on the sidelines. That means 20-year-old Kieran Marmion continues at half-back but Elwood makes eight changes from the side that lost to Scarlets last time out with Mark McCrea and James Loxton replacing Fetu'u Vainikolo and Tiernan O'Halloran on the wings. Matthew Jarvis comes in at out-half while 19-year-old Robbie Henshaw gets his first start for the province at outside centre. Up front hooker Adrian Flavin replaces Ethienne Reynecke and he is joined in the front row by Brett Wilkinson and Nathan White. George Naoupu started at No.8 against Cardiff Blues and Zebre but he joins the second row alongside Dave Gannon who gains his first start after three consecutive weeks coming on from the bench. Willie Faloon, who made his Connacht starting debut last weekend, stars in the all-new back row trio which sees Johnny O'Connor move from openside to blindside flanker. And despite his injury headaches, Elwood is tipping his youngsters to step up. “With Frank's injury it is our job now to keep up-skilling our two young nines and make sure they are ready,” Elwood told the Irish Independent. “But they are two good lads and two good scholars of the game. “Kieran has been terrific and we have great faith in himself and Dave Moore. Paul O'Donohoe is going to be out for another eight or nine weeks with his hamstring injury.” At Scotstoun Stadium, 7.35pm. Referee: Alain Rolland (IRFU, 54th competition game) Assistant Referees: Peter Allan, Adrian Graves (both SRU) Citing Commissioner: John Kirk (SRU) TMO: Jim Yuille (SRU) Live on BBC ALBA and TG4