Kennedy was a surprise late insertion by John Morris in the Sharks' win over Penrith on Thursday, pushing star Josh Dugan to the wing.

"It was a big decision for me. I just felt that losing Matty Moylan, we just lose that creativity and natural fullback play," Morris said.

"And it was more about, I wanted Josh to go there on that right side and really stiffen us up defensively and put Josh outside Bronson (Xerri)."

Morris didn't inform Kennedy of his call-up until the captain's run on Wednesday, however, it didn't stop nearly 40 friends and family making the game.

And that included dad, William 'Bubba' Kennedy, who played 61 games for Balmain during the late 90s in the centres.

Kennedy senior is still playing in the country rugby league competition at 50 years of age.

"I've got a few video tapes at home that I used to watch when I was a little kid. It's good to watch him when he's out at group ten playing," Kennedy told AAP.

"I got parts of him in my game. I learned so much off him and my uncle Steven Lane.

"They're still out there playing Group 10, so it's good.

"He just told me to have a good game and rip in."

It was a nervous start for Kennedy, who started with the Sharks' SG Ball team before playing under Morris for two years in the under-20s.

But, on the day of his 22nd birthday, Kennedy slowly found his feet and was involved in a couple of their tries in a stirring comeback victory.

He finished the match with a modest 79 metres, but broke four tackles.

"In the first half I was heaps nervous but once I got into it, I felt pretty comfortable with the boys around me," Kennedy said.

With Moylan still sidelined with a hamstring injury, Kennedy is likely to retain the No.1 jumper for next week's clash with Brisbane.

"Started a bit shaky for our back three actually with a couple of errors there but I was really happy for Will Kennedy," Morris said.

Australian Associated Press