The Maple Leafs have a few players on the Marlies now who have cleared waivers this season. The most recent is Calvin Pickard, acquired today. Others are Garret Sparks, Kerby Rychel and several other depth player options should the Leafs be very pressed for callups.
If any of these players are called up to the NHL, they can stay on the NHL roster for 29 days or nine NHL games. This accumulates, so if a player is moved up and down, the days add up and the games add up from the time they last cleared waivers. It also doesn’t matter which team you were on when you cleared waivers, all that counts is days and games in the NHL.
Once they’ve played their 10th game or hit 30 days, they have to go through waivers again the next time they are sent to the AHL.
Updated to add: the so-called 30-day clock does not start until the regular season begins. So preseason days in the NHL do not count.
And now you know!