 In his second season with Bilbao, Bertāns helped the team to reach the 2015 ACB Playoffs as the fifth seed, but they eventually lost to Valencia in the Quarterfinals.In July 2015, Bertāns joined the San Antonio Spurs for the 2015 NBA Summer League, where he averaged 11.3 points, 3 rebounds and 1.6 in three games played for the Spurs.On January 20, 2016, Bertāns recorded a season-high 27 points, shooting 6-of-11 from three-point range, along with four rebounds and two assists in a 76-78 loss to Bayern Munich.