There will be no “Sacha magic” to illuminate proceedings at the Aviva Stadium on Saturday evening. Instead, the Stormers will place their trust in Jurie Matthee to steer their attack against Leinster in the absence of one of South African rugby’s brightest talents.Sacha Feinberg-Mngomezulu suffered an ankle injury while scoring a try in the Stormers’ 44-21 United Rugby Championship (URC) quarter-final victory over Cardiff. He left Cape Town Stadium on crutches and was subsequently diagnosed with a syndesmosis injury that will sideline him for months.With scrumhalf Cobus Reinach also unavailable, John Dobson’s side travel to Dublin without last season’s starting Springbok half-back pairing as they attempt to secure a first appearance in the final since losing to Munster three years ago.Feinberg-Mngomezulu’s absence is a significant blow. The 23-year-old was nominated for World Rugby’s Breakthrough Player of the Year award in 2024 and has emerged as one of the game’s most exciting attacking talents.Last October he scored 37 points against Argentina, breaking Percy Montgomery’s long-standing Springbok record for points in a Test match. He was later named South Africa’s Young Player of the Year and Players’ Player of the Year.Stormers' Sacha Feinberg-Mngomezulu leaves the pitch on crutches after the Cardiff match. Photograph: EJ Langner/INPHO The responsibility now falls to Matthee, with the Stormers expressing confidence that the 25-year-old can fill the void.“Injuries are part of the game,” Stormers assistant coach Rito Hlungwani said. “It’s always tough losing players, but it’s also an opportunity for other players. Sacha is injured, so Jurie comes in. It’s part of the game and something we feel we can handle.“There will be no trouble at all for the other players getting used to Jurie because they train with him all the time and he’s also played a lot of games for us, many of them quite tough games.“He has always been ready to step in. We are confident he will come in and do a good job for us.”Feinberg-Mngomezulu brings unpredictability and flair – or “X-factor” as Leinster full-back Hugo Keenan described it this week – while Matthee is more of a traditional fly-half in the mould of Morne Steyn or Handre Pollard, offering a dependable kicking game.[ ‘I was gutted’: Hugo Keenan using Champions Cup heartache to fuel Leinster’s URC bid ]Leinster know all about him. Matthee started at outhalf when the Stormers hammered the province 35-0 in Cape Town in the opening round of the season last September. Although Leo Cullen’s side were missing their British and Irish Lions contingent, the scale of the defeat still came as a shock.Matthee contributed 20 points that day, scoring a try and adding three conversions and three penalties.Since then he has made 17 appearances this season, including seven starts, bringing his total to 16 starts from 31 games since joining the Stormers from Western Province in 2023. His last start at No.10 came in the Champions Cup round-of-16 defeat by Toulon.“If you look at our first URC game against Leinster, Jurie was the fly-half that started and it worked really well for us then,” Hlungwani said.“Jurie is someone who is ready to step in. He’s never really been out of the team. He’s played tough games for us, so we’re quite confident he’ll come and do his thing.“We really like players to play to their strengths. Jurie will fit in nicely. If it changes anything, great, because he’ll be playing to his strengths. But there’s no particular change of plans in terms of how we play.”Keenan warned against underestimating Feinberg-Mngomezulu’s replacement.“Matthee started against us when they put a good number on us. He’s still a top-quality outhalf. In his own right, he’s a top-quality 10,” he said.“I think their kicking game is a big part of it. They kick a lot, whether it’s off nine or off 10. So that aerial battle is something they focus on. They’ve got strength and depth in their squad, in fairness.”Dobson believes his team can cope without their first-choice outhalf. However, winger Seabelo Senatla is a major doubt as he works through concussion protocols, while lock Ruben van Heerden is also struggling after suffering a head knock against Cardiff.“Seabelo was absolutely magnificent for a guy who has been out for so long,” Dobson said. “He was imperious in the air, on defence and with his work rate. Sacha, we can live with it, but Seabelo’s injury is massive. It was an expensive game, those injuries.”