The Canadian Soccer Association confirmed the injury news Wednesday. Matheson, who has made 161 appearances for the national team over her career, was scheduled to see an orthopedic surgeon later this week.
"Our primary goal is to make sure she has the best care for this first stage, until that happens we are unable to comment on her timelines," the CSA said in a brief statement.
Matheson, from Mississauga, Ont., remained hopeful that she'll be back in time to compete at next summer's FIFA Women's World Cup in her home country.
"Obviously I want to be in a World Cup so that’s my goal," she said on the CSA Twitter account.
Recovery time for a torn ACL is different for every athlete, but it typically takes at least six months to a year. The 2015 World Cup is scheduled to begin June 6 and lasts about a month.
The timeline presents a stiff challenge for the 30-year-old Matheson. She has just over seven months to not only recover, but also regain her top form on the pitch.
Matheson scored the lone goal in Canada's 1-0 Olympic bronze-medal victory against France two years ago. She left Saturday's friendly at Edmonton in the 78th minute and was on crutches afterward.
Matheson overcame an injury to her other knee in time to participate at the 2012 London Games.
"I had surgery the November before (the Games) as well," she said. "Hopefully I can make a similar comeback."
However, Matheson was not a quick healer on that occasion.
She was originally tabbed to need six weeks to recover from microfracture surgery to repair torn cartilage, but ended up missing six months and had to skip the Olympic qualifying tournament in January 2012.
As World Cup hosts, the Canadian women don't need to go through the qualifying stages this time around. Instead they'll play a series of friendlies to keep sharp in advance of the tournament.
Japan defeated Canada 3-2 in another friendly on Tuesday night in Vancouver. Japan won the 2011 World Cup and took silver at the London Olympics.