 Pari gbolohun ti o tẹle: A firanṣẹ Mitrofanov lati ka ẹkọ ni Ile-ẹkọ giga Ologun fun Mechanization ati Motorization ni Kínní 1933 ati lẹhin ti o pari ni Oṣu Karun ọdun 1937 di olori ti ẹka oṣiṣẹ 2nd ti 5th Mechanized Corps ti Agbegbe Ologun Pataki ti Belorussian. Lati Oṣu Kẹwa ọdun 1938, o ṣiṣẹ bi olori ti ẹka oṣiṣẹ 1st ti 15th Tank Corps, ti a ṣẹda lati 5th Mechanized Corps. Ni agbara yii, Mitrofanov kopa ninu awọn : Iṣẹgun Soviet ti Polandii ṣaaju ki o to wọ Ile-ẹkọ giga ti Ogun ti Awọn Oṣiṣẹ Gbogbogbo ni Oṣu kejila ọdun 1939, eyiti o gboye ni ọdun 1941. 