Greenacre has missed the last couple of matches with a knee problem and it now seems the injury could be worse than initially feared.

"We'll see on Monday, when the time span will be a lot clearer," coach Ricki Herbert told the Dominion Post.

"Given the short run in now, hypothetically if Chris is out for four to five weeks, then we need to discuss that and get to the market quickly."

Goalkeeper Mark Paston is also on the treatment table while several other members of the squad are just one booking away from a ban, including skipper Andrew Durante.

Ben Sigmund and Manny Muscat are serving bans as a result of ill-discipline during recent matches.