Cronulla captain Wade Graham's future is under a cloud after he suffered another head injury.

Graham hurt his head in the first half of the Sharks win over Penrith when attempting to tackle Robert Jennings. Graham underwent a HIA which he ultimately passed but was then ruled out with a hyperextended knee.

Channel Nine commentator Phil Gould said Graham's technique left himself open for a head injury and needed work.

"Bad technique, that's really bad technique," Gould told Channel Nine.

"Head-on, low tackle, head to the side. It's his technique that gets him in trouble.

"Those head-on tackles, I don't care what age your kid is, head-on tackles - don't let them tackle like that.

"He's had a number of concussion issues and they've all been the same way - making tackles with poor technique down low."

Graham has had to end his night prematurely on two occasions this season due to failed HIA's but has had more knocks than just those two.

He passed a HIA against the Melbourne Storm in round eight but he didn't return to the field after that incident.

Former Sharks skipper Paul Gallen said he was concerned for Graham after the series of blows to the head he has taken this season.

"I had no doubt he had a head knock there," Gallen told Nine.

"I think the reason his knee gave way was because things weren't working properly.

"He definitely got up and hyperextended his knee, but I think it was because he wasn't in total control of his body.

"Fingers crossed he has passed the HIA and there's no further issue with his head because has had a couple of bad ones this year. No doubt his knee is the issue at the moment."