Courtney and Ingall are good friends and former teammates, both from Ingall's Walkinshaw Racing days in 2012-13 and Stone Brothers Racing from 2006-07.
'The Enforcer' Ingall retired at the end of last season to become a FOX Sports expert commentator, but will dust off the helmet to do double duties in the next few weeks, racing and testing the #22 HRT Commodore at Winton next week in preparation for Sandown.
"I've been very happy and comfortable working with FOX SPORTS on its V8 coverage, but when the call came to help out a mate I didn't hesitate," Ingall said.
"Jack's also a mate and while he's disappointed not to be driving with James as planned, we've driven together in the past and he understands the need for an experienced replacement.
"I know the guys on the team, they know me well, so at least there's some hope of getting a result."