Help! Crop Bound Chick???

[MimiChicken]

I am not a newby to raising chicks but I may have made an unwise decision.
I put my 2 week old chicks out in the sun and they loved it. I included their feed, water and chick grit.
Evidently my Americanas thought the grass was prerty neat stuff. I saw them nipping at it.
Now, two of the three have very large crops and one of them is looking mighty poor, indeed.
Any helpful words?
Once about 20 years ago I had a beautiful Banty hen that I gave vegetable oil to and massaged the crop. She recovered nicely. But how much would I give a chick or is there another (better) remedy?

 

[hinkjc]

How long ago were they on the grass? Also, what do you mean when you say the chick is looking poor? You can take the food away overnight and see if the crops go down by morning. If so, resume feeding only chick starter. If not, we'll need to move this to emergencies.