Scorching weather and India's refusal to play a day-night match have dented attendance at Adelaide Oval for the start of the first Test between India and Australia.
Thursday's final crowd of 23,802 is the lowest turnout for day one of a Test since the stadium was redeveloped in 2013.
Local officials had flagged that ticket sales were down compared to past years, and walk-up attendances are certain to have been affected by the 39C heat.
The mercury is set to reach 38C on Friday before a cool change over the weekend.
Adelaide has hosted day-night Tests since 2015 but India refused Australian pleas to play the series-opener as a day-night fixture.
A whopping 55,317 fans packed out the ground for day one of last year's pink-ball Ashes Test.
"It has been an issue, it has affected ticket sales," Bradshaw said on Tuesday.
"One of the characteristics that we have noticed is that we are quite down in interstate sales given it's a day Test not a day-night Test.
"There is definitely a day-night factor, without a doubt.
"The fans have absolutely voted with their feet the last few years that we have had day-night Tests, we have been significantly up for attendances."
Bradshaw still expected overall crowd numbers to surpass the previous best of 113,000 for an Adelaide Test between Australia and India, set in 2014.
But another complication was a South Australian government decision to cancel all train services in Adelaide this weekend.
No trains will run because international experts will be in Adelaide to relocate the control centre from the city to the northern suburbs in a decision which was protested by the SACA and Cricket Australia.
DAY ONE TEST ATTENDANCES AT ADELAIDE OVAL SINCE REDEVELOPMENT
55,317 - 2nd Test v England, 2017*
47,441 - 3rd Test v New Zealand, 2015*
33,943 - 2nd Test v England, 2013
32,255 - 3rd Test v South Africa, 2016*
25,619 - 1st Test v India, 2014
23,802 - 1st Test v India, 2018
* Day-night Test
