Culina was a notable absence in the Sky Blues' 2-1 win over Brisbane at Allianz Stadium on Sunday after being ruled out following his training-ground bust-up with Farina on Friday.
The victory lifted Sydney back into the top six for the first time since round four while Italian legend Alessandro Del Piero became the club's most prolific scorer - his 11th goal a record haul for a Sydney player in a single season.
Besart Berisha levelled with a first-half penalty but it was young midfielder Peter Triantis who sealed the win, opening his Sky Blues account with his 69th-minute strike.
The victory lifted the Sky Blues into sixth spot while Brisbane dipped to eighth.
Del Piero again proved the difference breaking the deadlock in the seventh minute after masterfully moving past the Roar defence while his classy passing game created chances for Sydney.
But while many thought Culina was the Sky Blues' missing link, it seems the 32-year-old has played his last game for Sydney after making only eight appearances since signing with the club last October.
The club is set to meet during the week to discuss the matter but asked in an on-field interview after the match if Culina will play again this season Farina responded: "That will be determined next week, but at this stage no."
Farina was not willing to discuss the issue with reporters in a media conference later.
"I'm not going to talk about that now, this is not the forum," he said.
"If you want to talk about the game, we'll talk about the game.
"What happens in our club is our business."
Farina concedes the club's inconsistency has been a "roller coaster ride" in the 11 weeks he's been at the helm.
He says getting three points against his former side on Sunday was crucial but admits maintaining a finals spot will be tough.
"That's the million dollar question isn't it," he said when asked if Sydney can stay in the top six.
"I hope so, put it that way. But next week against Adelaide is a huge game for us as was this one.
"So that was a big three points for us here tonight."
He praised former Juventus player Del Piero but was far from pleased with Brett Emerton and Ali Abbas whose yellow cards will see them suspended from next weeks' clash with the Reds.
"He's a big game player and we certainly need him," he said of the 38-year-old Italian.
"He's stepped up at a time when the club has been desperate for his experience and his play."
Roar coach Mike Mulvey said while his side didn't have their best day, Del Piero was just too hard to combat.
"You've got one world class player out there," he said.
"He's a player who makes the difference, he makes things happen."