Striker Jerome Sinclair joined Blues on the final day of the January 2017 transfer window on a Standard Loan from Premier League Watford until the end of the season.
Blues fought off interest from several other Championship clubs to secure the services of the highly-rated former Liverpool striker, who has an abundance of pace and very good technical ability.
Birmingham-born Sinclair joined Watford last summer for £4m after failing to agree a new deal with the Reds.
During his time at Anfield the former England Under-17 international became the youngest ever debutant for the club, when he made his debut at the age of just 16 years and six days old.
Since making the switch to Vicarage Road, Sinclair has made six appearances, the most recent of which was in January 2017 in the the FA Cup, when the Hornets lost 1-0 away at Millwall.