"We both didn't know what to do with it," said the 29-year-old Canadian rugby international.
The Winnipeg centre got it put back in and, for a while, managed the shoulder problem. But the separations continued and an MRI revealed she had two tears in her labrum that had started to progress to her bicep tendon.
Marchak waited until the 2013 Rugby World Cup Sevens to have surgery, going under the knife in August that year.
She was back playing rugby 4 1/2 months later and is expected to be one of the Canada's weapons as the 15-woman version of the IRB Women's World Cup kicks off in France. The Canadian women open Friday against Spain.
All 12 captains, including Canada's Kelly Russell, posed for a photo Tuesday with the Eiffel Tower as a backdrop.
Canada, which finished fourth in 1998, 2002 and 2006, is in a pool with England, Samoa and Spain. The three pool winners and the runner-up with the best record advance to the semifinals.
New Zealand has won the last four tournaments, defeating England in the last three finals.
It will be the Victoria-based Marchak's fifth World Cup. She also competed at the 2006 and 2010 15-woman tournaments and the 2009 and '13 sevens versions of the World Cup.
"This one, I guess, is special on so many levels ... I'm actually at full strength, I'm at full fitness. I get to be part of this team," she said.
And five-foot-five Marchak, like her teammates, believes this Canadian squad can beat anyone when it is playing its best.
She spent the first two weeks after the right shoulder surgery with her family in Winnipeg. Marchak, who is right-handed said she needed their support.
"They honestly were a godsend," she wrote in her blog. "I was not in a good place. I can't even sugar coat it.
"The first six days were the worst of anything I had experienced. I didn't sleep well, my mom had to sleep on the couch next to me when I woke up to help me. I cried myself to sleep for the first little while (slept on my back for almost 2 1/2 months). I watched a ridiculous amount of Netflix, and I am pretty sure I got sick of being in my own company."
Months later, she has a slightly different view.
"It was hellish but I don't think I would trade that experience. It really opened up my eyes to a lot of things," she said in an interview.
Russell watched her friend and teammate fight her way back
"Rugby's her life and what's what she focused on," she said. "She's very committed to anything she does."
Only now is Marchak able to do everything with her shoulder that she could before the injury.
"With that comes tightness and a little bit of aches but it's stronger than it ever was," she said.
Marchak has run over more than her share of opponents on the rugby field but thinks the injury was more due to years of training.
She is one of some 20 women, all connected to the national sevens side, who are centralized in Victoria. Others moved to train with them, while there are also pockets of players elsewhere.
Despite the geographical differences, Marchak describes the Canadian team as "very, very close." Some of that bonding came on a June tour Down Under where Canada blanked Australia 22-0 and lost 16-8 and 33-21 to New Zealand.
She recalls the trip to New Zealand where the women would take their morning coffee together at a picnic table — "make sure everyone's good, catch up." And then get to work.
"Coming together on the field, everyone gets along so well."
The women also got to see a lot of New Zealand's Maori heritage on tour.
"As long as I've played, I've never been on a tour where we go to experience so much of the culture — and a culture that is so built around unity and strength and community and family. To be a part of that was unbelievable."
Marchak who made her debut for Canada in 2005, started off as winger and fullback before moving to centre. Her preference is outside centre but she has also played in the No. 12 shirt.
She can beat opposing defenders but, if that doesn't work, will also run over them.
Marchak has played overseas, spending most of 2010-13 with the Saracens' women's side in England.
"Probably one of the best experiences of my life," she said. "I met a lot of really amazing people. But not only that I got to play an international (calibre) game almost every weekend, playing against those girls."
Marchak has her eye on one more season in England, but only after the 2016 Olympics, where women's rugby sevens makes its debut.