It depends, every cherry eye is different for every dog. My Blossom developed cherry eye at the age of 5 months, and I was able to massage it in for a short while, but then it wouldn't stay in anymore. We had her eye repaired at 7 months at the same time as we spayed her. A week later her other eye popped out and it wouldn't stay in, and was actually bigger than her first eye. We had a second repair surgery a month later to repair the eye. That was 3 years ago, and we haven't had any problems with her eyes, and they healed beautifully, you wouldn't know she ever had surgery on her eyes. How old is Archie?, if he is still a puppy, you can wait and see if it stays in or continues to pop out and discuss this with his vet.
You can buy over the counter eye drops from the pharmacy like Saline Drops, or a Dry Eye Formula drops to put in his eye to help keep it from getting irritated and to prevent it from drying out.