S.L.
Some kids need to suck longer than others. I am not so big on taking it if they are using it only for nap and bedtime if it is still a big deal to them. Some kids are 'babies' longer than others and I don't mean that in an unkind way. If you feel it has to go then let him suck on blankets and hope he won't go to the thumb which is much harder to break.