Knights five-eighth Jarrod Mullen has had an injury-plagued 2016 NRL season.

Experienced Knights playmaker Jarrod Mullen's preparations for next season have been interrupted by a recurrence of a hamstring injury that plagued him throughout 2016.

Mullen managed 14 appearances in 2016 after playing just 10 games the season prior. The 29-year-old won't require further surgery after re-injuring the hamstring at training this week, but admits he's likely to be troubled by his hamstring for the remainder of his career.

"It is not going to be as strong as it usually is," Mullen told the Newcastle Herald. "If it keeps going it will be pretty hard to get back. 

"I just have to be patient with it, and hopefully it gets stronger before the start of the season. It is frustrating for me and the club that it went again. But it is not as bad as last time.

"I was just squaring up at the line and it went again.

"I just have to get into the rehab and keep doing all the right things, like I have been doing.

"I have to grit my teeth and keep going… fingers crossed it holds strong."