I came across a case that had this interesting piece in it while discussing some IAC claims.
A defendant’s constitutional right to testify in his own behalf is implicit in the Fifth, Sixth, and Fourteenth Amendments. Rock v. Arkansas, 483 U.S. 44, 51-53 (1987). However, "[w]hether the defendant is to testify is an important tactical decision as well as a matter of constitutional right." Brooks v. Tennessee, 406 U.S. 605, 612 (1972). "Although the ultimate decision whether to testify rests with the defendant, he is presumed to assent to his attorney’s tactical decision not to have him testify." United States v. Joelson, 7 F.3d 174, 177 (9th Cir. 1993). A defendant’s "silence" after his attorney decides not to call him as a witness implies that he has waived the right to testify on his own behalf. See United States v. Pino-Noriega, 189 F.3d 1089, 1095 (9th Cir.) cert. denied, 528 U.S. 989 (1999).
As noted in Pino-Noriega, the failure to testify should "not be raised as an afterthought after conviction." Id. at 1096. Rather,