Sydney Sixers development rookie Ollie Davies, 18, along with 19-year-old Sydney Thunder wicketkeeper-batsman Matthew Gilkes, from Ulladulla, have both been added as rookies.

Thunder allrounder Daniel Sams and fellow left-arm quick Greg West, who made their Sheffield Shield debuts last season, were both upgraded to full-time contracts in a squad to be captained by gloveman Peter Nevill.

Davies made headlines last season when he peeled off 207 from 115 balls at the Under 19 National Championships as captain of NSW Metro. He became the first player to score a double century during a one-day match in that tournament.

Gilkes performed strongly in Futures League.

Opening the batting, he made 508 runs at an average of 46 for ACT/NSW Country and scored 51 on BBL debut for the Thunder.

"They're both very, very exciting prospects for New South Wales and Australian cricket," Cricket NSW general manager of cricket performance David Moore said.

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Super star international batsmen Steve Smith and David Warner rejoin the squad, among six Blues contracted with Cricket Australia, including pace trio of Pat Cummins, Mitchell Starc, Josh Hazlewood and off-spinner Nathan Lyon.

Former Australian Test opening batsman Phil Jaques enters his second season in the role of Head Coach after taking the Blues to the Sheffield Shield final last season.

Jaques said the stability within the squad was very important.

"There's a real stability with the lack of changes within the squad and it's probably a testament to the season that the team had," Jaques said.

The Blues made their first Shield final in five seasons and showed significant improvement, particularly with the bat.

Across both formats, limited-overs and Shield cricket, 12 centuries were scored as compared to six during 2017/18.

With the ball, Steve Waugh Medallist Sean Abbott, fellow quick Harry Conway and veteran seamer Trent Copeland, all posted career best Shield seasons.

Six players made their First Class debut for NSW, all of whom retained their contracts, including teenagers Jack Edwards and Jason Sangha, who scored their maiden Shield centuries within minutes of each other against Tasmania at the SCG.

Edwards was also named JLT One-Day Cup Player of the Year for the Blues to cap off a remarkable debut season. He scored 273 runs at 54.6 and became the youngest ever batsman to score a one-day domestic century in Australia.

Nick Bertus and rookie wicketkeeper-batsman Baxter Holt were the other two First Class debutants.

"When you try to develop players, you want to give them an opportunity to do well," Jaques said.

"We obviously want to reward performance as well which we've done with the changes that we've made."

"I think the long-term development of the core group of young guys is still, very, very important, as is the leadership that the (senior players) have shown over the last 12 months."

Moore emphasised the same point.

"After Phil and his coaching staff had done such a great job last year, the players really bought into the changes that we wanted to make ... it was important to keep that stability and build upon last season," Moore said

"We have got a healthy balance of youth and experience."

Davies and Gilkes are two of six rookies in the squad with Holt, paceman Ryan Hadley, fiery left-arm quick Chad Sammut and opener Ryan Hackney.

Holt, 19, set a new record for most dismissals by a NSW wicketkeeper on First Class debut last season, equalling the record for a First-Class debutant in Australia, with nine catches against Tasmania in Hobart.

Seamer Charlie Stobo, fast bowler Henry Thornton, off-spinning allrounders Arjun Nair and Chris Green, wicketkeeper Jay Lenton and batsman Jordan Gauci were delisted.

NSW Blues 2019/20 contract list: Peter Nevill (c), Sean Abbott, Nick Bertus, Harry Conway, Trent Copeland, Ben Dwarshuis, Jack Edwards, Mickey Edwards, Daniel Fallins, Ryan Gibson, Liam Hatcher, Moises Henriques, Daniel Hughes, Nick Larkin, Stephen O'Keefe, Kurtis Patterson, Daniel Sams, Jason Sangha, Param Uppal and Greg West.

Cricket Australia contracted: Pat Cummins, Josh Hazlewood, Nathan Lyon, Steve Smith, Mitchell Starc and David Warner.

Rookie contracts: Ryan Hackney, Ryan Hadley, Baxter Holt, Oliver Davies, Matthew Gilkes and Chad Sammut.