Liam Knight, perhaps as soon as Sunday afternoon, is poised to become known for something other than claiming the worst driving offence in NRL history.

Not for the first time, Knight's immediate future is in the hands of others. The Manly forward is within reach of a first-grade debut after being named as part of a five-man bench against Penrith. Whether he makes the cut depends on how several injured teammates pull up from from fitness tests, while the salary cap auditor will also have a say in the matter.

The season is only at the halfway point and already the Sea Eagles have been forced to use 27 players, such is the injury toll. This has placed a strain on the club's second-tier salary cap, meaning special dispensation will be required for Knight to become the 28th. Their injury woes worsened on Thursday with Steve Matai ruled out for the rest of the year with a neck problem.

Knight knows what it's like to be beholden to Rugby League Central. In a moment of madness, he was clocked doing 137km/h in a 70km/h zone. Hoping to beat the breathalyser, he grabbed a can of Aeroguard and sprayed it into his mouth. After counting to 10, he registered 0.176. Given that he was on his P-plates and had form, the NRL could have put a line through him forever.

While his actions were inexcusable, it's not the only dark road the 21-year-old has gone down and the Sea Eagles were keen to stick by Knight for reasons outside his undoubted potential. The Berkeley Vale Panthers junior lost his mother when he was five, his father has been in and out of his life and he has bounced around foster homes all over the country. He has also watched as his brother has struggled with associated issues.

Which is why those close to him are hoping he can fulfil his ambition and run out against the Panthers at Brookvale Oval.  "He's a tough bugger, but he's still a work in progress," said coach Trent Barrett. "We're going to have to help him with that, it's ongoing. Just because you force your way into a first-grade side doesn't mean your issues are solved. It's a great effort from him to get there from where he was, a few months ago it wasn't looking great for him, but he's done well.

"He has [learned from his mistake], definitely. He understands it was silly and could have ended up a lot worse than what it did.

"We all make stupid mistakes when we are young and we need to keep supporting him. He's been really good over the last few months, he's got good people around him, there are good leaders here in Nate Myles and Jake and Killer and other senior players. They've taken him under their wing and really helped him."

Should the forward pack originally chosen get through the final training sessions unscathed, Knight may yet have to wait another week or so. But it's only a matter of time before the former junior tennis star gets an opportunity to showcase his talents on a grander stage. "I've named him in the squad, more as a reward for his last month of footy," Barrett said.

"He's been really good, doing everything right, he's training hard and become one of the most consistent young players in the NSW Cup while playing big minutes. I'd like to see him get a run sooner rather than later, he deserves it. With the injuries we have, we'd have a pretty fair argument to play him."

The 13th-placed Sea Eagles are also without halfback Daly Cherry-Evans, skipper Jamie Lyon and forward Brenton Lawrence. They take on a Penrith side that has also made plenty of changes, not all of them forced. Five-eighth Jamie Soward will be part of a reserve grade team that also includes hooker James Segeyaro. Nathan Cleary, the son of former Panthers coach Ivan, retains his place in first grade after making his NRL debut against the Storm last weekend.

"When I was at the Warriors, he was the ball boy," said Manly forward Lewis Brown.