Sanja Mandic stood out already as a very young player in Radivoj Korac and played with Serbia NT in the U16 European Championship played in 2010, reaching the Semifinals. One year later, in the 2011 summer, Sanja Mandic was the best scorer and the second best passer in the U16 European Championship after averaging 22.7 points, 7.3 rebounds and 3.9 assists per game.
Sanja Mandic played again the U16 European Championship in 2012 and she won the Bronze Medal and averaged 10.6 points, 3.1 rebounds and 2.8 assists per game.
In the 2013 summer, Sanja played the U19 World Championship in 2013 and she averaged 7.8 points, 3.9 rebounds and 2.8 assists per game. Also, Sanja starred in the U18 European Championship and she won the Bronze Medal with Serbia and avearged 11.6 points, 5.4 rebounds, 4.6 assists and 3.4 steals per game, being the best passer and the best in steals in the whole championship.
In the 2013/14, summer, Sanja Mandic played with Radivoj Korac and she averaged 8.9 points and 4.2 rebounds per game in Serbian League and 7.5 points, 4.1 rebounds and 3.2 assiss per game in Adriatic League, having a very successful season in which she was Serbian League, Serbian Cup and Adriatic League Champion.
In the 2014 summer, Sanja Mandic played the U20 European Championship and she averaged 8.4 points, 3.6 rebounds and 1.9 steals per game, reaching the Semifinals. Also, Sanja played the World Championship in Turkey with the Serbian Senior National Team.
Santa Mandic stayed in Radivoc Korac during the 2014/15 season and she averaged 11.4 points, 4 rebounds and 4.1 assists per game in Serbian League and 12.4 points, 5.2 rebounds and 4.8 assists per game in Adriatic League, being again Serbian League Champion and being named in the Adriatic League First Team after reaching the final of the competition.
In July 2015, Sanja Mandic played the U20 European Championship and she averaged 8 points, 3.2 rebounds and 3.7 assists per game.
Sanja Mandic played her final year with Radivoj Korac in the 2015/16 season and she averaged 10.5 points, 3.9 rebounds and 5.5 assists per game in Serbian League and 14.6 points, 4.5 rebounds and 5.1 assists per game in Adriatic League, being named again in the Adriatic League First Team and becoming Serbian League Champion for the third consecutive time.
In the 2016/17 season, Sanja Mandic signed in Hungary with PEAC Pecs and she averaged 8.8 points, 4.5 rebounds, 5.3 assists and +14.3 efficiency in 28 minutes per game in Hungarian League and 9.9 points, 3.6 rebounds and 4.7 assists per game in the Eurocup, shining against Kayseri with 18 points, 6 rebounds and +22 efficiency. In the Hungarian League, Sanja was the 3rd best passer in the competition.
Sanja Mandic re-signed with PEAC Pecs in the 2017/18 season and she had a very good performance with 10.8 points, 4.5 rebounds and 6.5 assists per game in Hungarian League and 10.8 points, 4.2 rebounds and 6.2 assists per game in the Eurocup. Sanja was the Hungarian League second best passer.
Sanja Mandic started the 2018/19 season in Poland with Torun and later she moved to Hungary, reaching the Hungarian League Semifinals with Uni Györ.
Sanja Mandic started the 2019/20 season with Crvena Zvezda and she averaged 9.5 points, 4 rebounds, 8.7 assists and +19.8 efficiency per game in Serbian League and 7.8 points and 6.8 assists per game in Adriatic League.
|2019/20||CRVENA ZVEZDA||ADRIATIC LEAGUE||7.8||2.5||6.8||28||42%||28%||69%||2.3||0.5|
|2015/16||RADIVOJ KORAC||ADRIATIC LEAGUE||14.6||4.5||5.1||29||47%||26%||80%||1.5||0.1|
|2014/15||RADIVOJ KORAC||ADRIATIC LEAGUE||12.4||5.2||4.8||30||42%||29%||83%||1.9||0.1|
|2014/15||SERBIA||U20 EUROPEAN CHAMPIONSHIP||8.0||3.2||3.7||31||30%||20%||66%||1.6||0.1|
|2012/13||SERBIA||U19 WORLD CHAMPIONSHIP||7.8||3.9||2.8||27||43%||21%||66%||1.3||0.1|
|2012/13||SERBIA||U18 EUROPEAN CHAMPIONSHIP||11.6||5.4||4.6||27||45%||26%||62%||1.3||0.1|
|2011/12||SERBIA||U18 EUROPEAN CHAMPIONSHIP||10.6||3.1||2.8||29||34%||30%||87%||0.9||0.1|
|2010/11||SERBIA||U16 EUROPEAN CHAMPIONSHIP||22.7||7.3||3.9||34||43%||29%||77%||2.6||0.2|
- Second best passer | Hungarian League 2017/18
- Third best passer | Hungarian League 2016/17
- First Team | Adriatic League 2014/15, 2015/16
- Serbian League Champion 2013/14, 2014/15, 2015/15
- Serbian Cup Champion 2013/14
- Adriatic League Champion 2013/14
- Best in steal | U18 European Championship 2013
- Best Passer | U18 European Championship 2013
- Bronze Medal | U18 European Championship 2013
- Bronze Medal | U18 European Championship 2012
- Serbian Cup Finalist 2011/12, 2012/13, 2014/15
- Fourth best in steals | U16 European Championship - 2011
- Second best passer | U16 European Championship 2011
- Best scorer | U16 European Championship 2011
- U16 European Championship 2010 Semifinalist