Western Australia 7 for 436 (Green 185*, Whiteman 114) trail New South Wales 6 for 443 dec by seven runs

There is a sense of uncertainty in Australian cricket about how soon 21-year-old Cameron Green should be promoted to the national set up - it's a question of when, not if - but a career-best 185, as he batted throughout the third day against New South Wales, suggested as a batsman he is not far away.

Green's impressive stay, which followed a century from Sam Whiteman, led a strong Western Australia response as they closed within touching distance of the New South Wales total. Unless there is an agreement between the captains on the final day - or the defending champions stumble in a nothing-to-gain third innings - it is difficult to see how there will be a positive result on a docile surface.

Green's technique and composure stood out as he did not lose his patience when kept quiet in the 80s and bombarded by a sustained short-ball attack which occasionally had him in some awkward positions, although the gentle nature of the pitch made it a back-breaking tactic for the quicks.

He brought up his fourth first-class hundred from 250 balls when he drove Nathan Lyon through the covers and he was still there at stumps having faced 378 deliveries. He is being held back from bowling in the early stages of the season after a series back problems but even without that part of his game he could be in the selection frame.

Whiteman had resumed on 81 and brought up his fifth first-class hundred from 193 balls before the third-wicket stand of 173 was ended when he top edged a pull into the leg side to give Sean Abbott his third scalp early in the afternoon session. Whiteman's run of Shield scores since the second part of last season reads 53, 4, 51, 110, 65, 18 and 114.

It was a day of toil for the New South Wales attack, but Harry Conway was rewarded for a hard-working spell when Ashton Turner edged to gully although there was never a suggestion of a clatter of wickets that would have opened up the game.

Ashton Agar settled in alongside Green to further chip away at New South Wales' advantage until he was trapped lbw by his opposite number Lyon. There had been some concern earlier in the day when Lyon appeared to be feeling some discomfort in his right shoulder after attempting a run out attempt during the first session, but he was able to send down 40 overs and added Aaron Hardie leg before with one that gripped nicely.

Andrew McGlashan is a deputy editor at ESPNcricinfo