you want to try to keep the sprout with the dirt around it... can you water the plant in the bag and let the dirt clump around the seedling and then gently transplat it into a regular pot..bringing the dirt with it

try to get a 3-5 gallon pot. that way you wont have to transplant again.

a baby plant like that can not handle much trama and they often go into shock (whatever that means) when the dirt is pulled away from the tap root..... for some reason baby plants in dirt don't have the resilience of clones in rockwool..

good luck