Siegenthaler ayaa la tartamay kooxda Switzerland ee tartankii 2013, 2014
iyo 2015 IIHF World U18 Championships. Ciyaartii cajiibka ahayd ayaa la aqoonsaday markii loogu magac daray 2015 U18 WJC All-Star Team. Waxaa sidoo kale loo doortay inuu ka qeyb galo tartanka xuska Ivan Hlinka ee 2014.