Unleashed?

What does a card set Unleashed mean? ie: 2019u Thanks

Unleashed set has a few extra players that played little during regular season---Sam Hilliard is an example--though they can play the whole season and are priced accordingly--on-line has no use restrictions.

Welome to the game BoomWinning.

Here are the extra players in the 2019U set:

Austin Hays OF
Sam Hilliard OF
Sean Murphy C
Reese McGuire C
Kyle Lewis Of
Kyle Tucker 1b/OF

Sean Manaea SP
Tyler Glasnow SP
JB Wendleken RP
Aaron Civale SP
Jameson Tallion SP
Tony Gonsolin RP
Austin Voth S/R
Dustin May S/R
Alec Mills S/R/C

Thanks!