This is always a stressful time of year for Major League Baseball’s 30 general managers, who are evaluating talent, juggling financial implications and trying to figure out ways to make their teams better as Tuesday’s trade deadline approaches.

Now there’s another factor in the wheeling-and-dealing calculus — Covid-19 vaccination status.

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“It’s certainly one of the things that’s new that you didn’t have to think about,” Pirates GM Ben Cherington said. “I think every team obviously wants to feel that the full complement of their roster is available to play, but we’re in a new world and there’s personal choices.”

Those personal choices matter because MLB’s Covid-19 rules affect all 30 teams differently.

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Arizona Diamondbacks GM Mike Hazen said the vaccine status of players was affecting trade talks “to some degree” but didn’t believe it would be a deciding factor in many deals, particularly for teams that don’t have to travel to Canada in the near future.

Hazen added that vaccine status is part of a player’s medical file, so there shouldn’t be any secrets, since teams are free to discuss those details.

As the only MLB team located in Canada, the Toronto Blue Jays have by far the toughest constraints. Foreign nationals who aren’t vaccinated against Covid-19 are not allowed to enter Canada, save for limited exceptions that require a 14-day quarantine.

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Unvaccinated players are placed on the restricted list, where they are not paid and do not accrue major league service time.

That means any upgrades for the Blue Jays — who are right in the middle of the American League playoff race — will almost certainly have to be vaccinated. It also means teams travelling to Toronto for the rest of the regular season have to consider if they’re willing to add a player who might miss a crucial series.

The Yankees, Guardians, Rays, Orioles, Red Sox, Angels and Cubs all play games in Toronto after the Aug. 2 deadline. Toronto GM Ross Atkins declined an interview request through a team spokesman.

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Several teams have gone to Canada this season without some of their best players. The Kansas City Royals were the most extreme example, losing 10 players ahead of their trip north of the US border.

Several of those players — including hitters Andrew Benintendi and Whit Merrifield — have reportedly been the subjects of trade talks. Benintendi was traded to the Yankees last week. Merrifield, a two-time All-Star, says he may be willing to get the vaccine if it means playing postseason games in Toronto.