The stint of time that a player has to spend on the injured list is returning to 15 days for the 2022 season, per reports. Since the 2017 season, the injured list had been 10 days, but under the new CBA it appears that the 15 day injured list is returning.
In addition, players that are sent down on an optional assignment must now spend at least 15 days in the minors before being recalled, rather than 10 days.
These changes, along with the new rule limiting the number of times a player can be optioned in one season to five times, are presumably motivated by a desire to reduce roster churn.