The talented 22-year-old is transferring north to Waitakere United. It is a great opportunity for the Dunedin-born and bred left back to play for one of the league's leading clubs.
In that sense, it was an easy decision to make. But telling his Otago team-mates he was leaving in the middle of the season to chase his dream was difficult.
''I trialled for them at the start of the year and the coach said the door would be open in the transfer window just after Christmas, so away I go,'' Prattley said.
''It is a great opportunity and puts me in good stead to go on with my career. But it was an extremely tough decision to make because I've played for Otago for the last four or five seasons.
''And being captain, seeing them struggle at the bottom, well, it is not somewhere you want to leave the team you play for.
''But it is just what I have to do to go further in my career. Telling my team-mates wasn't the easiest thing to do, but they understand what I need to do.''
Otago United coach Richard Murray described Prattley's departure as a ''massive loss'' but he wished the player well.
''He will play in the O-League as well, so it's a massive opportunity for him,'' Murray said in a text from Vietnam, where he is holidaying.
''It's a shame it is in the middle of the season but I can understand his going and wish him well.''
Prattley's influence at the back and on the team will certainly be missed. He was one of just two Otago players named in the league's team of the month and he produced a strong performance in Otago's only win this season - 1-0 against Wellington.
Otago United is on the bottom of the competition table with one win from seven matches, while Waitakere is at the other end with six wins and a draw from seven games.
Waitakere has qualified for the group stage of the O-League and if it wins that tournament, it will qualify for the Club World Cup.
A chance to play in tournaments of that calibre was a powerful drawcard for Prattley, who leaves for a holiday in Thailand today and will miss Waitakere's round eight game against Wellington.
