Tonight at 8:00pm ET is the deadline for teams to add players to their 40-man roster and thereby protect them from this year’s Rule 5 Draft. In other words: there will be a significant amount of 40-man roster moves made over the course of the next 13 or so hours. Six clubs already made moves to protect prospects from the Rule 5 yesterday, and each of the remaining 24 clubs should make moves today as well.

In brief: players drafted/signed at 18 years of age or younger must be added to the 40-man roster within five years of signing or be exposed to the Rule 5 Draft. Players drafted/signed at 19 or older must be added within four years. Those interested in all of the specifics can refer to articles from MLB.com’s Jonathan Mayo and J.J. Cooper of Baseball America. Perhaps of greater interest is that Mayo lists all of the prospects from MLB.com’s Top 100 list and from their organizational Top 30 lists that much be protected in advance of tonight’s deadline, while Cooper provides brief write-ups on each player that has been protected (and will continue to do so as additions are made).

Here are today’s additions to the 40-man roster. You can check out Baseball America’s coverage to learn more about the individual players listed below …