Wests Tigers playmaker Josh Reynolds will argue that "bruising" found on his ex-partner was not the result of violence, but instead a side-effect of "medication" she had been taking.

Mr Reynolds was present in Sutherland Local Count on Wednesday when a not guilty plea was entered for his domestic violence charge after allegations he had attacked his ex-partner, Arabella Del Busso, 29, in September. He allegedly left bruising on her right arm and left leg during the incident.

Lawyer Dan McGirr said there would be "a lot" of "expert" evidence that demonstrates the bruising was the result of medication use and not violence. Mr McGirr said "medical history" and "Centrelink and Medicare" documentation would be used as evidence to outline "what she was on and the effects that may have on someone".

Mr McGirr said the court would also hear from multiple "credibility witnesses" during the two-day hearing.