The All Whites man, who has been plagued by groin injuries during the past couple of years, will see a specialist on Thursday but has already been ruled out of internationals against Honduras and Paraguay next month.

The injury is not a recurrence of the groin injury Lochhead had surgery on prior to the World Cup but Phoenix and All Whites coach Ricki Herbert is resigned to losing his left-back for a lengthy spell - anywhere between eight to 16 weeks.

"We'll know in the next 24 to 48 hours. It could be a longer-term injury," he said.

"I think in fairness to him too it needs to be taken care of properly now. I think [surgery] is the only option now."

Herbert has decided not to add another player to his All Whites squad for next month's games in Auckland and Wellington, choosing instead to stick to a 20-man squad.

But the coach's immediate concern is Friday's A-League match against North Queensland Fury in Wellington.

Having mooted the idea of using a back three formation following the signing of Jade North, Herbert ruled out that as an option against the Fury leaving Manny Muscat, who has being playing well in a defensive midfield role, as the likely contender to slot in at left-back.

"I'm reluctant to move him out of midfield," admitted Herbert.

"I think he's cemented the quality in there for us. But it's [what's best for the team] and he's probably the most adept to slot into that role."

Herbert also has concerns over Paul Ifill who is has a niggling groin injury. The star striker did not train on Wednesday and will be given as long as possible to prove his fitness.

"We've had to back up three pretty big games in a short period of time," said Herbert.

"I don't want to risk anybody. It probably wouldn't be my preference [to rest Ifill on Friday]. We'll give him the time."

The coach did not rule out changes in the front third though after seeing points go begging during the Phoenix's week-long stay in Melbourne which produced a goalless draw against Victory and a 2-1 loss to Heart.

"I think we created a lot of chances when we were away but we haven't taken them. Tactically we might play a bit differently," he said.

"If Chris [Greenacre] plays we'll maybe get a little bit more support to him - an attacking minded player. Nicky Ward could play in there.

"He's been exceptionally good for us in the front third of the pitch. I think we've got some good options there."