The 18-year-old signed for the club around Christmas and has made a good impression.
The team is unbeaten in its past four games and it was the first side to take points off Auckland City this season when it held the premiership leader to a 1-1 draw at Sunnyvale on Wednesday evening.
Deeley made a couple of strong runs and nice touches. The young fullback is probably better suited to the right side of the field but he is doing a good job for the team on the left.
Southern United coach Paul O'Reilly has been suitably impressed with his teenage charge.
''He is young, he is exciting and has a lot of good qualities,'' O'Reilly said.
''He is technically very good in possession. He is physically small but he makes up for that with really good decisions.
''And he can dribble and beat players and is totally an exciting player.''
Pity, then, that he plans to leave soon. The former national under-17 representative was born in United Kingdom but moved with his family to Timaru when he was 8.
He has spent the past two years attending Auckland Grammar and is a bright lad with plans to pursue a college scholarship in the United States. There are offers on the table but he is still deciding which one to accept.
He will leave for the United States in May but would ''definitely like to come back and play at some point''.
''I've got a few years at college over in the States and then I'll see what happens from there. But it would be nice to pay them [Football South] back.
''They've given me a lot of opportunities as a young player and I hope to play for them again in the future.''
Well, that is if his future does not include a Major League Soccer contract.
''My goal would be to try to get picked up after college in the MLS. That would be the ultimate goal for sure.''
The next goal is to make the New Zealand under-20 squad for the World Cup in Poland later this year.
He has been invited to a camp in April and hopes to impress enough to get the opportunity to go to a second age-group World Cup. He was part of the New Zealand team which contested the under-17 World Cup in India in 2017.
More immediately, though, he has a game against Tasman to play in Nelson tomorrow.
Southern United is looking to build on a strong finish to the season. It beat Tasman 3-1 earlier in the season and that was despite losing a player to a red card early in the match.
But Tasman has signed half a dozen or so players during the transfer window and is expected to offer stiffer resistance.
Southern may be without the services of striker Garbhan Coughlan and defender Conor O'Keeffe. They were struggling with the flu earlier in the week.
