While the Cowboys put on a magnificent display against the Penrith Panthers, they will be sweating on the status of forward Heilum Luki.

Although Luki went off for a HIA and was cleared, the club's medical team were wary that he may have endured a potential fracture.

Heilum Luki did pass his HIA but there is a possible fracture that they are a little bit worried about, so he won't return tonight,” Brent Tate said on Fox League at the time.

The second-rower returned from an ACL injury this season after a long lay-off. Unfortunately, the injury caused him to miss last year's finals, where the Cowboys made it to the Preliminary Final against the Eels.

After beginning this season on the interchange, he has taken one of the starting back-row positions since Round 10 against the Sydney Roosters.

In his nine games this season, Luki has scored two tries, had two line breaks and ran on average 82 metres. In defence, he has made 204 tackles with a 91.5% efficiency rate.