re: Lange and Hess called up to Tigers 60-man roster

This is only the 60 player pool. The actual roster is 30 players. According to MLB's Operating Manual, all players on a 40-man roster “that the Club anticipates participating” during the season will be part of the player pool, while the rest will be made up of non-40-man roster players under contract. Any 40-man-roster players who are not included in a player pool (for example, maybe a prospect who isn’t deemed ready for the Majors) will still be paid during the season. No team will be allowed to exceed the limit of 60 players in its player pool at any time during camp or the regular season. Per MLB rules, teams must cut their rosters to 28 after 14 days of regular season play, which will begin on July 23 or July 24, and 26 after 29 days. Additionally, each club can carry up to a three-person taxi squad on the road once the regular season begins.

Players not on the active roster do not accrue Major League service time, so prospect clocks do not start unless they’re added to the active roster during the regular season.

Not saying they might not get called up and this is certainly good news that they are on the top prospect list and may get a chance if some of those on the 30 player roster spots get sick, but not very likely they will get called up to actually play in a game.