In an interview with the Los Angeles Times on Tuesday, the director of the National Institute of Allergy and Infectious Diseases warned of the potential dangers of letting the Major League Baseball season go too far into the fall.

"If the question is time, I would try to keep it in the core summer months and end it not with the way we play the World Series, until the end of October when it's cold," Dr. Anthony Fauci told The Times. "I would avoid that."

When to end a potential season has been a significant point of contention between MLB and the players' union.

The league has been consistent in its insistence that the regular season end Sept. 27, citing health concerns, as well as the desire of national TV partners not to have games extend into November. The union's most recent proposal of 89 games would have had the regular season end in mid-October.

Coronavirus cases have been on the rise even in warmer areas of the country as some states begin to reopen. But Fauci said that if baseball is to be played, it should be done mostly in the summer.

"This virus is one that keeps fooling us," Fauci said. "Under most circumstances -- but we don't know for sure here -- viruses do better when the weather starts to get colder and people start spending more time inside, as opposed to outside. The community has a greater chance of getting infected.

"The likelihood is that, if you stick to the core summer months, you are better off, even though there is no guarantee. ... If you look at the kinds of things that could happen, there's no guarantee of anything. You would want to do it at a time when there isn't the overlap between influenza and the possibility of a fall second wave."

The potential for a season of any length is currently unclear, as the commissioner's office is refusing to set a schedule unless the union waives its right to file a grievance against the league.