He was caught in the tail wind of South African Wayde van Nierkerk 's world - record 400 run earlier in the week and settled for bronze .
Merritt looked equally relieved after the men 's 4x400 .
Merritt was caught in the tail wind of South African Wayde van Nierkerk 's world - record 400 run earlier in the week and settled for bronze .
Merritt looked equally relieved after the men 's 4x400 .