Cosier struggled with his weight throughout his career, in part due to his back trouble – a permanent condition since birth: a vertebra is out of alignment. "I can't do any heavy physical work at all", he said in February 1977. "I can't run or do gym work." Move to South Australia He relocated to South Australia to play regular first class cricket. "I wasn't getting many runs, and one day keeper Ray Jordon told me to get across to Adelaide", he later recalled. "I thought no more of it until Ray, now a newspaper columnist, wrote a story saying I would definitely be going to South Australia". This resulted in a series of offers from Adelaide clubs which prompted Cosier to move in 1974. Coming under the influence of South Australian skipper Ian Chappell, Cosier pursued his positive approach to batting and seemed to be headed for the top, although Chappell doubted his commitment to the game. Highlights of the 1974–75 summer for Cosier included 81 against Victoria. International Cricketer 1975–76 Season Cosier had an excellent season with the bat in 1975–76. He leapt into test consideration with 130 for South Australia against the touring West Indians. He followed this up with 76 against NSW, and a match winning 49 against Queensland. He was named in a 13-person Australian squad to play a one-day international against the West Indies. Cosier pressed his claims with 71 and 49 against Victoria although he injured his hamstring in the second innings at had to bat with a runner. Cosier made his international debut for Australia against the West Indies in a one-day game. He took 1-33 and scored 25 not out, helping guide Australia to a five wicket victory. He was duly selected in the test team for the third test, replacing Terry Jenner. Cosier celebrated this by promptly scoring another century for South Australia against the West Indians, 107. Test Debut Cosier scored a century on debut. Cosier later recalled: I remember going out to bat at 5pm and Andy Roberts had just taken the second new ball. I had a really close lbw decision when I had scored about five. I knew I'd hit it but I didn't know that Robin Bailhache, the umpire, knew that I hit it. But thankfully he gave me not out. I went into lunch the next day at 99 not out and I was