Instead of departing for home, "Walker" received orders to replace in antisubmarine exercises in the Sea of Japan. These exercises included the Japan Maritime Self-Defense Force and naval units of the Republic of Korea. On 24 July, a Soviet "Kotlin"-class destroyer was sighted as it commenced shadowing the Allied group. "Walker" was designated to shoulder the Russian destroyer, and she was successful in preventing the attempted penetration of the screen by the Russian ship and her replacement. "Walker" also assumed duty on 29 July as a shadow against the Soviet electronics intelligence (Elint) trawler "Izmeritel".