Career
Although he is primarily recognised as a right-back, he is equally capable of playing on the right wing. Born in Zürich to a Gambian father and a Swiss/Italian mother, Janko began his career with Football Club Zürich before signing for Manchester United in 2013. After a loan spell with Bolton Wanderers, Janko moved to Scottish club Celtic in 2015.
He has played international football for Switzerland up to under-21 level
Manchester United
Janko joined Manchester United from Football Club Zürich on summer transfer deadline day in 2013. He was one of only three signings made by David Moyes during the 2013 summer transfer window.
On 26 August 2014, he made his first-team debut in a League Cup match against Milton Keynes Dons, playing the first half before being substituted for fellow debutant Andreas Pereira as United lost 4–0. = Bolton Wanderers (loan) On 2 February 2015, transfer deadline day, Janko joined Championship club Bolton Wanderers on loan for the rest of the season, with Andy Kellett going in the opposite direction for the same period.
He crossed to assist Eiður Guðjohnsen"s equaliser before half time, before scoring himself in the 80th minute from 25 yards out.
Celtic
On 1 July 2015, Celtic announced that they had signed Janko on a four-year contract.