Date of birth
Millwall secured the signing of Calum on a two-year deal from Burton Albion on 25th August 2016.
The 25-year-old central midfielder came through Tottenham Hotspur's youth ranks and has previously played for Barnet, Hayes & Yeading United, Dundee United and Danish side FC Hjorring.
He joined Burton Albion in 2015 and made 43 appearances for The Brewers as they were promoted to the Championship from League One last season.
Calum made his Millwall debut as a sub in the 3-1 win at Chesterfield just two days after joining The Lions and went on to make 40 appearances, scoring twice, against Northampton Town and Bury, both away from home.