(CNN)NBA players who are unvaccinated against Covid-19 will soon not be allowed to travel to and from games in Canada.
In a league memo sent Tuesday and obtained by CNN, the NBA warned teams that, due to Canadian laws, those players who have not received the vaccine and do not have approved medical or religious exemptions will not be allowed to travel to games against the Toronto Raptors, Canada's lone Canadian team, starting January 15.
No major professional sports league in the United States has required its players to be vaccinated.
A league source tells CNN 97% of NBA players are vaccinated, with 60% of eligible players having received a booster shot. With about 500 players across all the 30 rosters, the travel restrictions would impact approximately 15 players.
The league stated, due to US travel requirements, any unvaccinated player holding temporary visa status in the United States, would not be allowed to reenter the US should that player have left the country to play a game in Canada, or for any other reason.
The memo warns any player not complying with the travel mandates will be subjected to suspension and fines.
Tuesday's NBA memo specifically states all teams must report back to the league by Friday which players remain unvaccinated, and that the memo has been distributed to them.
On November 19, the government of Canada announced adjustments to its border measures which included updated entry mandates for previously exempted professional and amateur athletes. Only fully vaccinated individuals can enter the country starting January 15.