Aly was a part of the Germany under-21 team which won the 2013 Junior World Cup. He made his debut for the senior national team in February 2015 in a test match against South Africa. In December 2019, he was nominated for the FIH Goalkeeper of the Year Award. On 28 May 2021, he was named in the squad for the 2021 EuroHockey Championship and was named as a reserve for the 2020 Summer Olympics.