The side played at the ground for the second time in its national football league season yesterday, having moved there after spending last season at Peter Johnstone Park.
While not using it as an excuse for the 2-0 loss to Canterbury United, he felt the surface was "not really conducive to playing good football".
With the side having bounced around home grounds over the past two seasons — it has also hosted games at Forsyth Barr Stadium and the Caledonian Ground — O’Reilly felt the city’s grounds were in a poor state.
That included Tahuna Park, Forrester Park, Logan Park and Memorial Park.
"I’ll be honest. I’ve been in the [head coaching] role 18 months and we haven’t been on a decent surface other than the [Forsyth Barr] Stadium," he said.
"This surface that we’re playing on for national league football is genuinely an absolute embarrassment and a disgrace.
"Everyone involved needs to hold their hands up and acknowledge how bad it is.
"Our training ground is just as bad down at Tahuna [Park]. So every time we train, we’re training on a surface that is just as bad as this.
"In general the grounds in town are pretty shocking.
"Is it the reason we lost today? By no means am I making the excuse that it was the ground.
"But just as a spectacle, to turn up and have to play on this, it’s not the most motivating factor for playing for Southern United."
It comes less than two weeks after the ground’s No1 cricket wicket — alongside several other grounds — was ruled out of play because of safety concerns.
O’Reilly felt the all-weather turf proposed for Logan Park needed to be built and ready as soon as possible.
