Brad Haddin cranked up his preparations for one of the toughest jobs in world cricket - replacing Adam Gilchrist.

Less than a week after Gilchrist exited the international stage, the next wicketkeeper in line scored an entertaining 113 as NSW zeroed in on a home Pura Cup final at the SCG.

Haddin and Dominic Thornely (146no) put the Blues in a near impregnable position as the home side compiled 6-446, a lead of 318, at stumps on day two in reply to SA's 128.

It was Thornely's first ton of the summer, he and the unbeaten Beau Casson (75no) demoralising the rudderless Redbacks late in the day as the visitors used nine bowlers.

And if the day isn't enough to put a smile on Haddin's face, he recently found out his partner is expecting their first child.

"He certainly knew there was some great news for him with Adam Gilchrist retiring but there is also some great news for him on the family front as well," Thornely said.

The gloveman had been itching for a bat, having spent the majority of the past month as a spectator with the Australian one-day side during Gilchrist's farewell series.

Thornely said his teammate had to be patient as the tri-series doubled as a celebration of Gilchrist's career which restricted Haddin's playing opportunities.

"I feel for Brad you know this summer, having a beer with him last night it has been a hard summer for him as well," said Thornely.

"He has been in great form, he has really wanted to go out there and have a go with the Aussies but with the swansong that went on for a while. But I mean rightly so.

"But as we talk about reality I talk about my position in this team, Brad talks about his position in the Australian team.

"The strength of Australian cricket is outstanding.

"When you have players like Brad Haddin who sit on the sidelines, anywhere else Brad Haddin would have had 50 or 60 Tests by now and been one of the world's greats."

Haddin regularly made room for himself, lofting the ball just out of the reach of fielders on numerous occasions as he notched up 10 fours and two sixes.

His positive approach provided the impetus for the entire innings even if he did have a few jitters, spending 18 balls on 97 before reaching his third Pura Cup ton of the summer.

Set to become Australia's gloveman in both Test and one-dayers, it is just a matter of where and when for Haddin with the proposed tour of Pakistan in major doubt because of security concerns.

On the showing, the 30-year-old continues to have plenty to offer the national side with the bat as well as the gloves.

The innings was also noteworthy for Thornely's form revival following his lean pickings this summer, the red-head considering hernia surgery at the end of the season.

He took a much more measured approach, needing almost six hours to reach three figures as the Blues pinned down the uninspired SA outfit.

Usman Khawaja is expected to be squeezed out for the returning Michael Clarke for the final against Victoria starting Saturday.

The Blues need victory in this match to guarantee hosting rights for the final against the Bushrangers.

But the in-form Thornely didn't feel he was certain to play in the competition decider.

"I am still no guarantee to be in the team this week so I just have to keep putting my best foot forward," he said.