He initially picked up the painful injury in the Round 2 loss to North Queensland Fury and has missed training this week in the hope a rest may allow him to play.

The 28-year-old has battled with the injury for the last three weeks in an attempt to help the club through their early season form struggles and injury problems.

But the Socceroos midfielder is now rated less than a 50-50 chance to play against Phoenix, with Sydney to make a call on his fitness before they depart for New Zealand on Thursday morning.

With the Sky Blues to have the bye after the weekend's match, Sydney coach Vitezslav Lavicka is leaning towards resting his marquee man to ensure he is fully healed ahead of their following game against Gold Coast United on September 26.

"He (Carle) wants to play, he's a leader wants to help the team to get better results but we must manage it because we know he needs time for recovery to be 100 percent ready," Lavicka said today.

"We need him but 100 percent fit, it's hard to say now if he is. We will discuss with coaching staff and medical staff about him before we make a decision if he will travel."

The loss of Carle would be another huge blow for the winless defending champions, who are already without skipper Terry McFlynn (hamstring) and star striker Alex Brosque (ankle) for the trip across the Tasman.

The last-placed Sky Blues have endured a nightmare start to the season and are already nine points behind the league's top two sides.

Many believe Sydney's struggles are due to the fact they lost five of their most experienced players in the off-season in Steve Corica (retired), Simon Colosimo, Clint Bolton, John Aloisi (all Melbourne Heart) and Slovakian Karol Kisel.

But defender Shannon Cole dismissed that notion and said the team weren't using their departures as an excuse.

"This is the sixth week (of the season) now, there's no point thinking about the past," Cole said. "All those players have moved on ... it's part of football and we've got to deal with it.

"The squad's kind of let that go, it's you guys (media) that are still reminiscing about the past. All we're focusing on right now is the players that are available and team that's going to step on the park this week in Wellington."

While Phoenix again failed to find a win away from home in Perth last weekend, they are a much tougher proposition in Wellington, where they are undefeated in their last 22 matches.

"Those kind of streaks always come to an end at some point. It's our job and the task in front of us to make it happen," Cole said.

Lavicka hinted he would make some changes to his side after their woeful 3-1 home loss to Adelaide last weekend but he remained coy when discussing those possibilities today.

"We would like to change the results," he joked. "We know we have troubles in this moment and we will probably make some changes but it depends on which payers are available for this game.

"The main thing at the moment is the confidence of the players. If we have good confidence we have good players.

"I think this team is able to play good football but we need to get good results."