Green left the field on Friday at Canterbury as soon as he completed his 171-ball ton. Having reached his century with a quick single to mid-on both umpire and batting partner stretched out his legs (still with pads on) before he departed.
The issue was unsurprising given this was his first match since suffering soreness after playing an ODI in England in September. A month later he underwent back surgery after scans revealed a stress fracture, his fifth.
Green confirmed afterwards that he would be okay to continue his innings on day two, after "a good night's sleep and a bit of food".
"One hundred per cent I'm proud," he said of becoming the 10th player to score a first-class hundred on debut for Gloucestershire. "It's been eight long months on the sidelines so to get back out here was very special and it's always a good way to start your tenure.
Green has joined Gloucestershire for five four-day red-ball matches, concluding in late May, as he builds his match fitness with a view to playing for Australia in the World Test Championship final at Lord's in June.
The Australian came to the crease with his new county, who play in the second division, reeling at 3-41 against Kent.Â
Compatriot and county captain Cameron Bancroft, opening the batting, was one of the departed, leg before for two.
Green added 67 with Miles Hammond at four-an-over, before coming together with former England cap James Bracey. The pair, scoring at a similar rate, put on 167 before Green's exit after a little more than four hours batting.
Bracey went on to complete his own century, ending 109 not out at stumps as Glos closed on 7-365, Nathan Gilchrist taking 5-61.
Kent had been hampered by losing West Australian-born Italy international opening bowler Grant Stewart who pulled up having bowled 6.3 overs.
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