The village Elders gave him as thorough a workout as anything meted out by his trainers at the San Antonio Spurs, who re-signed him as their point guard in August for a reported $50 million ($65 million Australian).
"My trainer was worried about all the days of training I've been missing coming up here, but when he saw me doing my dance practice and the workout my legs were getting he said I'll be fine," Mills said.
Mer, also known as Murray Island, is a tiny dot of land, less than five square kilometers, that sits in the Torres Strait between Australia's Cape York Peninsula and Papua New Guinea.
Fewer than 600 people live there, according to the latest census, and in August the entire island came out to welcome home one of their most famous sons.
Mills is a Torres Strait Islander from his father's side and an Australian Aboriginal from his mother's.
As one of the most successful ever Indigenous Australian sportsman, Mills is a role model for many young Aboriginal and Torres Strait Islanders.
And in the Torres Strait, where he spent part of his childhood, he's considered nothing short of a hero.
Career on the court
Patrick Sammy Mills is the second Indigenous Australian to play the NBA after his cousin Nathan Jawai. They come from a strong sporting pedigree.
Their uncle Danny Morseu was the first Indigenous player to represent Australia in basketball, at the 1980 and 1984 Olympics.
Born August 11, 1988, Mills grew up in Australia's capital Canberra but spent time on Thursday Island, the administrative hub of the Torres Strait, and the home of his father Benny Mills.
Now 29, the younger Mills was first exposed to basketball when he was four years old, training with the Shadows, an Indigenous Australian team established by his parents who worked on government projects for Indigenous people.
By 16, he had accepted a basketball scholarship with the Australian Institute of Sport and by 18 had taken up a college scholarship at Saint Mary's College of California.
Mills made his NBA debut in 2008 at the age of 20 after signing with the Portland Trail Blazers.
He has been point guard for San Antonio Spurs since 2012 and has represented Australia playing for the Boomers in the 2008, 2012 and 2016 Olympics.
"It's been a very hard and long journey to get to this stage, but I want everyone to know that no matter what basketball jersey I put on, San Antonio, Australian Boomers, I represent everyone," Mills said in a speech to the Mer community in August, before performing his traditional island dance.
"What motivates me is you, so when I shine I hope you feel it too because you all shine too."
Remote South Pacific island
Traveling to Mer requires a 90-minute plane flight north of Cairns over the wilderness of Cape York, to Horn Island in the Torres Strait, then another 50-minute flight in a smaller plane east over the tip of the Great Barrier Reef.
Mer is one of three islands which are the remnants of an extinct volcano, but the island's traditional owners, the Meriam Mer people, believe Mer was formed by a boy named Gelam.
According to the legend, Gelam and his mother Usar were left alone on Moa Island in the central islands of Torres Strait where they were terrorized by an evil monster called Dhogai.
Gelam decides to leave Moa and his mother by building a dugong or manatee from a wattle tree and travels east to Mer Island where the dugong becomes a large hill in the shape of the animal.
Looking out from the plane window on the approach toward Mer, Mills points out the ridge line of the island and how it ties into the tale.
"See, that is the body of the dugong, facing back towards the Torres Strait from where he came," he said over the wail of the small plane's engines.
On arrival, visitors to Mer pass through a metal archway fashioned like the jaws of "Beizam," the tiger shark, an important totem animal.
It's not open to everyone; permission to visit the island must be granted by the traditional owners of this all Indigenous Islander community.
"The tarmac is under the law, Australian law, but as soon as you step through the shark's mouth and on to Meriam Mir land, you are under the lore, Meriam Mir lore," says traditional owner Doug Passi on the airport's landing strip.
Mer is revered throughout the Torres Strait for its strong cultural heritage but also as the "cradle of Native Title" after the successful Mabo High Court case in 1992, which recognized the land rights of Australia's Indigenous people.
The case was by championed by Mer islander, Mills' great uncle Eddie Koiki Mabo, whose grave on the island is now a sacred site, and where islanders pay their respects.
Reconnecting with culture
All scheduled engagements were canceled soon after Mills' arrival on Mer as his uncles stole him away for three hours of dance training.
After a traditional feast of lobster, clam meat, turtle, pickled fish and yams cooked in coconut milk, Mills had to perform the sacred Beizam shark dance, which is rarely seen outside Mer, in front of the Elders and the community.
The dance starts with a slow solemn drumbeat, played by Elders on the traditional wooden warup drum.
The three dancers, Mills in the middle, march in time to the center of the clearing, holding their shark mouth headdresses in front of them.
The headdresses are sacred emblems of the Malo cult, the Meriam Mir belief system that pre-dates the arrival of European settlers in the 18th century.
The chorus of wailing crescendos as the dancers put on their headdresses, biting down on a brace with their teeth, making their mouths become that of the shark.
They then spring about in unison, lightly on their toes, their arms out stretched as the turn left and right in movements that mimic the mighty Beizam hunting in the ocean.
The dance was once performed by the Zogo Le, the powerful sorcerer of the village. Today, it's an important rite of passage for Meriam Mir men. Mills had not performed it for more than a decade.
After dance training, Mills rested his aching legs in a deckchair in the common room of the Island Council lodge as he listened to his father, Benny, explain the importance of Meriam Mir culture.
"When you see Islander dancing it's important to understand it's cultural significance, not only to Meriam Mir people but all people of Australia."
"This is not like doing the 'bus stop', it's about a deeper level of understanding. It's not just part of Meriam culture but part of Australian culture and something all Australians should have an understanding about -- its part of all of us, it's part of not just being an Islander, but being an Australian."
Islander dancing is an integral part of the local Indigenous culture. Dances are performed at every social event from funerals to weddings. Everyone on the islands is taught the moves and their meaning, whether they're from there or not.
Mills, the role model
Mills is well aware of the responsibility that comes with being a role model to young Indigenous Australians.
He's recently published "Game Day!" -- a series of children's books about a young basketball player who overcomes challenges on and off the court.
Mills' visit to Mer was part of his new role as an official ambassador for the 2018 Commonwealth Games
to be held on the Gold Coast, Queensland, next April.
Basketball is on the program for the first time since 2006, but Mills won't be playing due to commitments with the NBA.
"I've always been an ambassador for Australians, non-Indigenous Australians and Indigenous Australians... I let people know about who I am and that I'm not just a basketballer, I'm a person who comes from a very rich heritage."
Based on the latest census, almost 650,000 people identified as Aboriginal and Torres Strait Islanders in Australia, about 2.8% of the population of 24 million people.
Typically, fewer Indigenous children finish school than non-Indigenous people, they have poorer health and earn less, despite successive governments' attempts to address historic failures and prejudice in the system.
Inspiring Indigenous children that they can achieve great things despite adversity is a message that Mills wants to share.
In 2014, after the San Antonio Spurs won the NBA Finals, he brought the Larry O'Brien Championship Trophy, which he nicknamed "Bala Lazza," to the Torres Strait.
The name itself represents a blend of cultures. In Meriam Mir, "Bala" means brother, and "Lazza" is Australian slang for Larry.
Mills and his teammate, fellow Queenslander, Aron Baynes carried the solid sterling silver and gold-plated trophy through the streets of Thursday Island.
The whole community got the chance to hold it and Patty, his father Benny and the Elders danced around trophy on the lawn into the night.
That sense of shared achievement is something Mills has brought all the way from the Torres Strait to Texas.
"He's just a special competitor, team player," Spurs coach Gregg Popovich said at a press conference in May.
"He's a big part of the spirit of our team. Whether he starts or comes off the bench, he's the same. Just a beautiful human being that energizes a whole group, and somebody that the group loves to be around. That's who he is."
For Mills, his culture is a source of celebration -- and strength.
He credits his ancestral ties with giving him the grounding to push for the top in the NBA, and for whatever comes next, off the court.
"I have been instilled with culture from such a young age that I know who I am, and I know once sporting is out of the picture, I will have this to come back to and continue the customs and traditions that I've been taught," Mills said.
"That's why it's special to come back here and continue that. Now I've just refueled the culture tank for another year so I will be able to go and do what I do."