[2] Simanić made his first EuroLeague appearance on 22 October 2015 in a 71–98 loss to Real Madrid, tallying ten points and four rebounds in 28 minutes of action.

[3] He was a member of the World Select Team that played in the Nike Hoop Summit in Portland, Oregon on 7 April 2017.

In September 2024, Simanić signed with the Bosnian Igokea returning to professional basketball after a year after his kidney injury.

[13] Simanić competed for the Serbian junior national teams at the 2013 under-16 European Championships,[14] winning a silver medal at the event.

[17] On 30 August 2023, while playing against South Sudan in 2023 FIBA Basketball World Cup, Simanić was struck in the kidney by Nuni Omot while defending the basket.