July 2nd 2016: "When David Weir was at Sheffield United, he asked if I had any Scottish relations and I said my grandad - and he thought I would be a great asset to Scotland and it just materialised from there," McFadzean explained.
Having come through the Blades' youth ranks, he only managed 23 appearances for the League One club and had loan spells with Chesterfield, Burton Albion then, last season, Stevenage in League Two.
"I had some disappointing seasons, missing out on promotion and it just didn't work out," he said. "I had my chances and then a new manager would come in and I had to start again."
McFadzean says that his ability to play several positions should help him win regular football at Rugby Park.
"Just a hard-working player who likes to get forward but also tracks back," he said when asked to describe himself. "A team player, but I obviously want to do well for myself as well.
"I think I am a versatile player, so you will see me in several positions over the season.
"I have played at the top of the diamond, left and right, at left-back and I've played at right-back as well." - BBC, 3rd July 2016
Mar 16th 2017: Callum has joined Alfreton Town until the end of the season and Russ O'Neill brings Callum into the side mainly to operate in the midfield.
Born in Sheffield, he came through the ranks at his home-town club, has also represented England at under-16 level, but has since opted to play for Scotland at under-21 level. He has had loan spells with Chesterfield and Burton Albion before having a short spell with Stevenage last season.
A product of Sheffield United's Academy McFadzean was a member of the team that reached the final of the FA Youth Cup in 2011, scoring in the first leg of the final against Manchester United. He was eventually promoted to the senior squad and made his professional début in the first game of the 2012–13 season, a League Cup tie against Burton Albion.
McFadzean made his first start for the Blades in the Johnstones Paint Trophy against Coventry City at the Ricoh Arena. After a number of first-team starts at the tail end of the season, McFadzean came off the bench to score the winning goal in the first leg of United's play-off semi-final against Yeovil Town. Following his successful end to the season McFadzean had had his contract with the Blades extended in June 2013.
Following the arrival of new United manager Nigel Clough, McFadzean joined Chesterfield in November 2013 on a short-term loan. McFadzean returned to his parent club in January 2014 after making five appearances for Chesterfield. In March 2014, McFadzean joined League Two side Burton Albion on an initial one-month loan. McFadzean remained with Burton for the remainder of the season, scoring one goal and making ten appearances for his temporary employers, including playing in Burton's unsuccessful appearance in the play-off final at Wembley.
In July 2014, McFadzean rejoined Burton Albion on a six-month loan deal but two months of his spell was on the sidelines with injury after breaking his fifth metatarsal bone in a match against Cambridge United.
November 2015 saw McFadzean join Stevenage on a one-month loan before the end of the 2015–16 season saw Callum released by Sheffield United. But in June, McFadzean signed for Scottish Premiership club Kilmarnock where he has made four appearances.