From Eniwetok, "Monssen" steamed, with TG 32.41 to Guadalcanal, where the Palau offensive was rehearsed. On 8 September, assigned to screen and provide fire support for TG 32.4, she headed west. On the 15th and 16th, she stood off Peleliu, shifting to Angaur on the 17th and remaining in the screen of that transport area until the 23d. On the 24th, she got underway for Manus Island, whence she departed 11 October for Leyte Gulf and her fifth amphibious landing.