Having not played football since round five, Wayne Bennett believes star back-rower Matt Gillett may not pull on the boots again this season.

Gillett suffered a fractured neck earlier on this season, and was scheduled to miss 12 weeks, although he suffered another injury setback recently that has stunted his return.

The 29-year-old sustained a calf injury at training, and is now at least two weeks away according to Bennett, although that could easily be a little longer.

After the Broncos' win over the Panthers on Friday, Bennett was asked about Gillett's recovery, and admitted he's unsure when, if at all, Gillett will return this season.

"I probably feel he probably won't play this year somehow. Something is telling me that," Bennett told reporters post-match.

"It is two weeks before he gets another scan, and that will be four weeks before the end of the season virtually."

With Gillett's last game coming in early April, it's expected he would need further time to work back up to full fitness and contact training, meaning it's now a race against the clock to see whether or not Gillett will return to the field in 2018.