In the wake of the death of Ginny Williams, the wife of founder and team boss Frank Williams, family members are staying at home rather than travelling to Melbourne.
Coughlan says that the absence of both Frank and daughter Claire, who is director of marketing and communication, means he will step up for any duties either of them would have been required for.
"It's for this weekend only, until Claire is able to come back," he said. "It is very much a temporary measure and it is very much in support of Claire.
"I am a great supporter of the family, Claire knows that and Frank knows that. I said I would take over from Claire this weekend and I see this as a very temporary measure. I am doing this to support Claire and Frank, and the whole family."
Teams members from the Grove-based outfit are planning to wear black armbands on race day as a mark of respect for Ginny Williams, and a book of condolence has been opened at its hospitality unit in the Albert Park paddock.
Coughlan said the news of her death has left the whole outfit with a great feeling of sadness ahead of the opening race of the season.
"Ginny was a great fan - and a great person," he said. "She always said that she was Williams' number one fan for two reasons: one she was the first fan, and secondly she cared more than anybody.
"I think there is great sadness; great sadness also as we were all away when it happened.
"I got to know in the airport and I was not able to pass my condolences to Frank – who I still see every day. But, on the other hand, we have to move on and I obviously hope we do well for Ginny's memory."