Newcastle boss Alan Pardew has insisted for several weeks that the 31-year-old striker would not be joining up with his country despite warnings from coach Stephen Keshi that he would demand FIFA took action if he did not.
Nigeria's media officer, Ben Alaiya, told BBC Sport: "Shola's refusal to answer calls gave Keshi no other option than to allow him to concentrate on his club.
"The coach and team secretary made several attempts to reach Shola but there was no answer. The coach waited to hear back from him but a call never came.
"A decision on the next move will be made at the appropriate time."