Cox, who brought up a century of career goals in January, joined Blues after his release from Sky Bet Championship side Reading in June 2016.

The Republic of Ireland international was announced as a Southend United player on a two-year deal in July 2016 and committed his future to the Blues until at least the summer of 2018.

In his first season at the club, he top-scored with 16 goals, including the 100th in his career goal, and assisted another nine to set him apart at the top of the pile.

The 30-year-old has featured 30 times for his country scoring four goals. The striker was also part of Giovanni Trappatoni’s Euro 2012 squad in Poland and Ukraine.

Cox's other former clubs include Swindon Town scoring 35 goals in 62 appearances, West Bromwich Albion and Nottingham Forest.