Newcastle's A-League injury crisis has continued with defensive utility Ben Kantarovski likely to miss the next month with a torn meniscus.

The 24-year-old had to be helped from the field after suffering the injury to his troublesome right knee late in the Jets' 2-0 home loss to Sydney FC on Saturday.

Coach Mark Jones initially believed it wasn't serious and that Kantarovski would be available for this weekend's trip to face Wellington Phoenix at Westpac Stadium.

However, scans on Sunday revealed the damage is enough to keep him sidelined for an indefinite period, with a firmer timeline to be established once Kantarovski sees a specialist.

Kantarovski, who made his Jets debut as a 16-year-old, has made 143 career appearances for the club - but has been plagued by injury the past few seasons.

He was already filling in at centre-back in the absence of injured stoppers Lachlan Jackson (ankle) and Daniel Mullen (knee), and his absence will put further stress on Newcastle's defensive stocks.

Jones, who last week said he would probably seek an injury replacement player to fill in for Jackson, may now have no choice but to turn to the transfer market for reinforcements.

Alternatively, he could look to their youth team, where highly-rated rookies Caio De Godoy and Solomon Vaiika are possible options.