Bumrah has been the star performer for India in the ongoing Border-Gavaskar Trophy so far.
"There's no way that's cramp. He was very ginger after the break in the first innings. He bowled again, not quite as slow in the second innings. I don't even know why he bowled that over [in the second innings]. That actually gave some secrets away to everyone," Fleming said while speaking on SEN Radio.
Fleming’s comment came after Bumrah was attended by the team’s physio during the 81st over of Australia’s first innings. However, he resumed bowling immediately, completing his over and delivering three more overs later in the session.
The right-arm quick bowled an over in Australia’s second innings as well but his speeds were considerably down, hovering in the range of 120-130 km/h, fueling speculations about his fitness.
Adding to the concerns, Bumrah did not take part in India's training sessions following the match, further intensifying doubts about his participation for the upcoming Tests.
Fleming slammed the decision to have Bumrah bowl under such circumstances, suggesting that it might have revealed a potential susceptibility.
"Siraj might be workload [related], but I'm bemused Bumrah bowled that over. They could have hid this. They showed their hand," he added.
Addressing the media after India’s 10-wicket victory in Adelaide, Indian skipper Rohit Sharma downplayed concerns about Jasprit Bumrah's fitness, highlighting workload management in a hectic five-Test series.
"We want Bumrah to be fresh and play all five matches. It's important to manage the bowlers," Rohit had said.
The Border-Gavaskar Trophy currently stands level at 1-1, with the third Test scheduled to get underway on December 14 at the Gabba.