Using relative entropy of coherence, we study the atomic coherence (AC) in the nonresonant Jaynes-Cummings model, when the atom is initially prepared in an incoherent mixed state and the quantized field is in a thermocoherent (Glauber-Lachs) state. The influence of the increasing average number of thermal photons, average number of coherent photons and detuninig parameter on the AC are examined, separately in detail. We found that increasing the mean number of thermal (coherent) photons over a fixed mean number of the coherent (thermal) field has a destructive (constructive) effect on the AC. In addition, we see that the increment of detuning parameter leads to decrement of AC. Remarkably, we observe that in the particular case of thermal field, the AC cannot be created.