Lyon goes into Friday's match at Allianz Stadium with the worst record of any regular kicker among the six teams vying for the 2013 premiership, managing just 77 goals from 115 attempts (67 per cent) this season.
It is by far his worst percentage since joining the Sea Eagles in 2007.
Sharks fullback and goalkicker Michael Gordon boasts a success rate of 86 per cent, while South Sydney's Adam Reynolds and Sydney Rooster James Maloney hold records at 90 per cent and 87 per cent respectively.
In attempt to iron out the kinks that have plagued his kicking game this year, Lyon reportedly had a private 45-minute session with Arnold - who coached the Central Coast to an A-League championship last season.
"He was laying the ball too flat on the tee and running too straight at the ball," Arnold told Sportal.com.au.
"I got him to go further around the ball so his shoulders aren't going before he kicks the ball.
"We fixed his run-up and got the ball going straighter and he started striking the ball better.
"It was a simple procedure to fix."
Arnold said goalkicking was an important part of rugby league.
"It can win or lose you a game," he said.
"I do watch rugby league and watch goal-kickers closely and I can tell what they're doing wrong, whether they are hooking or kicking the ball across the face.
"I helped Benji Marshall a couple of years ago and I'm happy to help Manly out whenever I can when they need help."