The Magpies have been relegated from the Premier League and will play in the Championship next season.
Mitrovic joined Newcastle from Belgian giants Anderlecht in the summer of 2015. The 21-year-old Serbia international striker has done relatively well, although he has not been consistent.
The talented young player scored nine goals and created 30 chances in 34 Premier League matches this season.
Mitrovic had a pass accuracy of 72% and a shot accuracy of 49%, and won 76 headers, 16 dribbles and 15 tackles.
The former Partizan youngster is very talented and is quite popular among the fans, although he does need to be careful about his temperament and stop making rash challenges.
It will not be easy for Newcastle to finish in the top six of the Championship next season, and they need to keep hold of their best players.