Yes, the famous veteran Siberian divisions deployed in the Far East to protect USSR eastern borders against a possible attack by Japan before Barbarossa. Due to one man, Richard Sorge and the trust of Stalin in his spy network in Japan, these were transferred west from October to November 1941 in time for the battle for Moscow.In 1938 the Japanese were certainly of great concern. What frustrated Stalin more is that the British and French were not negotiating in good faith, and were obviously refusing to unite vs Hitler.
The Japanese were still a concern to Stalin until the attack on Pearl Harbor. The Soviets still had to keep a lot of troops in the Far East even during Barbarossa.
Western historiography severely underestimates how much the situation in the Far East effected the decisions in their European theater, esp. in 1938-41 period. They treat it as two separate conflicts, when it wasn't so for the Soviets at all. Even the Soviet invasion of Poland in 1939 hinged on the events in the Far East. In that early Sept. of 1939, the majority of Stalin's focus is on Japan and not even Poland at all.
The whole period of 39-41 was a very closely run thing for the Soviets, and Stalin knew it as it was happening. They didn't have the luxury to create more enemies than they needed. They understood perfectly well that at the very least the survival of the regime was at stake.