Zelený started his youth career at
Sutherland Sharks, before moving onto
PCYC Parramatta, as well as
NSW Super League club
Fraser Park, before signing with
National Premier Leagues NSW club
Sydney Olympic. In November 2011, it was announced Zelený had travelled to India, and signed with
I-League club
Mohun Bagan A.C. for the
2011–12 I-League season, replacing fellow Australian and former
A-League player
Simon Storey. Zelený made his debut for
Mohun Bagan A.C. in the
East Bengal derby against
Kingfisher East Bengal F.C. in front of 100 000 spectators. Zelený received widespread praise for his good performance in his first game for
Mohun Bagan A.C., and would remain as a cult figure against
Kingfisher East Bengal F.C. for the remainder of his tenure at
Mohun Bagan A.C., earning the moniker of "Mr. Derby" amongst the supporters for his impressive performances against fiercest rivals
Kingfisher East Bengal F.C. In March 2012, Zelený signed for
Gresik United in the
Indonesia Super League. Zelený moved to
Kaya F.C. in the
UFL Division 1 for the 2013 season, under the tutelage of fellow Australian, David Perkovic. On 11 April 2013, Zelený added to his reputation of being a "big-game player", as
Kaya F.C. defeated rivals
Global F.C. in a memorable game, that saw
Kaya F.C. fight back from being 2–0 down, to win 3–2. This marked
Kaya F.C.'s first win against
Global F.C. in the club's history, and the first time
Global F.C. had lost, since February 2012. On 13 June 2013, Zelený and Kaya repeated the same feat against
Global F.C., coming from two goals behind to win the game 3–2. In doing so, Kaya ended Global's hopes of winning the UFL Championship, and became the only team in the competition to successfully defeat Global in both home and away games. Zelený ended the season having not lost a game whilst playing for
Kaya F.C. Churchill Brothers SC completed their foreign quota by signing Zelený from
Kaya F.C. Churchill Brothers would go on to qualify for the knockout stages of the AFC Cup for the first time in their history, and also finished the season as Federation Cup champions. ==References==