After a match-winning century in the first Test in Adelaide, Head subsequently contracted COVID-19 but Cummins said the 30-year-old was progressing well in his recovery.
Head flew to Brisbane on Tuesday but decided to rest in the team hotel rather than join the Australian team for their late afternoon training session at the Gabba.
AAP has been told he will train on Wednesday but is not in any doubt for the day-night Test that starts on Thursday. Head will observe COVID-19 protocols before and during the Test match.
"He's almost out of it. He's fine and feeling good," Cummins said of Head.
"Even if he's still (testing) positive he can play. There will just be a few protocols but he's pretty close to a negative."
Skipper Pat Cummins believes Marnus Labuschagne and Steve Smith (r) are ready to fire at the Gabba. (Dan Himbrechts/AAP PHOTOS)
Key batters Steve Smith and Marnus Labuschagne are yet to score Test centuries this summer but Cummins said he sensed that was about to change at the Gabba.
Winning the series 2-0 is the most immediate concern, but Australia have a challenging two-Test series against New Zealand next month in which it will be imperative the gun duo are firing.
"You see how hard they work in the nets and even the way they have gone about their innings they look like piling on a big 100 or 200 like we have seen them do in the past," Cummins said.
"Smithy in particular last week looked really sharp up at the top but just got a good ball. It feels like they are poised to have a big impact.
"This summer we are looking at it as a seven-Test summer. Away series are always the hardest ones to win so that two-match series against New Zealand is going to be huge.
"We'll focus on this week, but we do have a bit of an eye to getting all our players through and making sure they are firing for that New Zealand series."
The Test at the Gabba will start with the looming aftermath of Tropical Cyclone Kirrily set to make its presence felt.
Rain is forecast from Saturday so making headway towards a quick victory may be paramount for Australia with vital World Test Championship points up for grabs.
Last summer's Test against South Africa at the Gabba was over inside two days on a green top.
Pat Cummins says Tests where ball dominates bat are far more interesting than the other way around. (Matt Turner/AAP PHOTOS)
The first Test against West Indies only just went into the third day and Cummins said he was enjoying the ball dominating the bat for a change.
"I've played in Tests that have fizzled out into a five-day draw and everyone walks away feeling a bit empty," he said.
"Whereas I've played in two or three-day matches where everyone can't take their eyes off the TV for a minute.
"Ideally, you want it to go a bit longer than two days but you want it to be a good contest between bat and ball.
"A couple of the Tests this summer have been fantastic, feels like every session has importance and any side can win."
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