Career
During his early career at age of just thirteen Sedekerskis played for Kuršiai Neringa in the third-tier Lithuanian basketball league - RKL and averaged 10.6 points, 3.8 rebounds and 1.8 assists per 27 minutes. Next season he joined NKL club Klaipėdos Nafta-Universitetas. In 2013, Sedekerskis signed a "1+2+3" contract with Laboral Kutxa Baskonia.
On May 10, 2014 Sedekerskis led Baskonia junior team to bronze medal after scoring 34 points (2-pointers: 7/10, 3-pointers: 4/11, FT: 8/11), grabbing 10 rebounds and making two steals.
He averaged 11.4 points, 4.9 rebounds and 1 assist per 20 minutes of game action. In 2015, he represented Lithuanian U-18 team in 2015 International Basketball Federation Europe Under-18 Championship and averaged 12.6 points, 7.0 rebounds and 2.3 assists per game.
The trio was invited to play in the International Basketball Federation"s Youth All-Star Game during EuroBasket 2015.