Maddinson was struck in the helmet from a delivery bowled by Victorian paceman Scott Boland during the one-day clash against Victoria on Friday, but was subsequently cleared to play in the final on Sunday.

The batsman made three runs before he was dismissed.

"Nic began feeling unwell during the latter part of the final and subsequently failed a further concussion test after the match," Cricket NSW Doctor John Orchard said.

"As a result, he has been withdrawn from the Sheffield Shield squad due to fly to Brisbane today.

"Cricket Australia's concussion policy requires that players are monitored, including follow-up tests for signs of concussion in the days after a knock to the head."

The news comes just days after fellow NSW batsman Daniel Hughes was also struck in the helmet in the same one-day game. Hughes was substituted under the new concussion rule, and did not return.

Hughes was felled when he mistimed a bouncer from Peter Siddle. He was quickly back on his feet, but Orchard ruled that he was not fit to continue batting.

Hughes was subsequently ruled out for final, which NSW won by six wickets.

It was the first time a concussion substitution had been used. Cricket Australia implemented the new policy in the wake of Phillip Hughes' death. The new rule provides for a concussion substitute, who must be a like-for-like player, who once activated can bat, bowl and field as if they were part of the starting XI.

The concussion substitute was implement in men's and women's domestic one-day matches, the BBL and WBBL, as well as other Cricket Australia sanctioned matches. But after the International Cricket Council rejected the idea for use in first-class cricket, they will not feature in the Sheffield Shield.

The incident rattled Siddle, who was part of the Test side when Phillip Hughes died after being struck in the neck during a Sheffield Shield clash in 2014.

"He was definitely rattled. For that over and probably the one after, he was struggling for 10 or 15 minutes," Victoria skipper Matthew Wade said after the game.

"You start to just get back into the game slowly but surely. It's not a nice situation after what everyone's been through."

Meantime, Mitchell Starc has been named in a 13-man squad but will play a limited role in the game as he prepares for the first Test against South Africa at the WACA after recovering from a lower leg injury.

The NSW squad is: Steve Smith (c), Doug Bollinger, Ryan Carters, Trent Copeland, Ed Cowan, Ryan Gibson, Josh Hazlewood, Moises Henriques, Nathan Lyon, Peter Nevill, Kurtis Patterson, Mitchell Starc, David Warner.