Haven’t seen new diamond goby since I added it 3 days ago. At what point should I be worried?

[CursiveTexas]

About 3 days ago I added a diamond goby to my tank. I don’t have much experience with them myself but from what I can gather it seems like it’s not unusual to not see them for a while after they are added to a tank. My question is at what point should I be concerned? I think I know what rock it’s hiding under, but I definitely don’t want to disturb/endanger an already distressed fish by checking on it. At the same time, the thought of a potentially dead fish fouling up my tank has me anxious. Any advice?

 

[SilverBulletPRN]

Probably not for months... I thought my goby and pistol shrimp was dead, crossed them off for a month or so. They just randomly popped back up a few days ago. This isn't the first time that happened either.