CHICAGO (CBS) — Plans are moving forward for Major League Baseball, with teams beginning practices this week – but we also have some players starting to opt out.

Defending World Series champion Ryan Zimmerman of the Washington Nationals is one who will skip this season because of “family medical reasons.”

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So far, the Cubs and White Sox players and coaches are all in for the 60-game 2020 season. The Cubs did have two staff members test positive for COVID-19 at home, and they will be delayed in joining the team.

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No players have tested positive, but for the Cubs, Anthony Rizzo and Jon Lester are both considered high-risk as cancer survivors.

“To this point, we have not had anyone that’s talked to us about opting out as we sit here today, but that said, you know, I’ve seen in the last hour or so that three players around the league have opted out. I’m sure there’ll be more,” said Cubs General Manger Jed Hoyer, “and I feel like we have to respect that, and everyone’s going to come at these decisions from a different angle, but I don’t think anyone that plays in the Major Leagues is going to make that decision lightly.”

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“You guys have already mentioned some high-risk players that we have. We have high-risk family members at home – multiple players. So, you know, it only takes one slip-up from not only a player, just the entire group that’s traveling with us in this bubble we’re trying to create,” said Cubs Manager David Ross, “so it’s imperative that we stick to the plan, stick to the protocols, and I’ve definitely got some messaging lined up on that front.”