The Blues Academy graduate put pen to paper on his first 12-month professional contract in the summer of 2016.
Born in the Democratic Republic of Congo, Lubala grew up in Leicester and joined Blues in 2014.
An attacking midfielder or forward, Lubala made 22 appearances for Blues Under-23s in 2016/17 and helped them to make a strong finish to their league season.
He was rewarded with a new one-year deal, including a further one-year option, in the summer of 2017.
During the 2017/18 campaign Lubala was a regular once again for the Under-23s, turning out 18 times for the Development Squad.
It was also his breakthrough season with the First Team as he was given his debut as a substitute in Blues' Sky Bet Championship away fixture at Bristol City in April 2018.