The Holden Racing Team has confirmed its new engineering combinations following this week’s dramatic internal shake-up.

Technical director Alex Somerset has been placed on Garth Tander’s entry, while team stalwart Rob Starr rejoins James Courtney.

The changes come following the sudden dismissal of Tander’s former engineer Blake Smith and the standing down of Courtney’s Alistair McVean, as previously revealed by Speedcafe.com.

Englishman Somerset joined Walkinshaw at the start of 2014 following a brief stint at Nissan Motorsport, engineering Nick Percat and Lee Holdsworth in the 2014 and ’15 seasons respectively.

Initially slated for a workshop based role in his new position at the now two-car outfit, Somerset has been a regular fixture at recent events amid the squad’s struggles.

Starr is meanwhile a near 20-year veteran with Walkinshaw who was moved onto the team’s new Porsche GT3 program this season.

His last minute call-up for Hidden Valley sees a reunion with Courtney, having worked together with McVean on the #22 entry in recent years.

Walkinshaw managing director Adrian Burgess told the Supercars website that his drivers had lost confidence in their previous engineers.

“What we’re trying to do is reinstall some confidence with the drivers,” explained Burgess.

“At the moment both drivers have lost a bit of confidence with the car and those around them and we need to rebuild that.

“There’s always a lap-time in the setup of the car, but there’s always a lap-time in the drivers’ head and confidence as well, so we need to rebuild and repair that.

“It’s never nice making changes in the middle of the year but we’ve got to think of the bigger picture.

“We’ve got to do the right thing for the business and if a fresh set of ears and eyes on the other end of the phone and looking at the data is what provokes a change of performance, that’s what we’ve got to do.”

Team owner Ryan Walkinshaw is set to attend Hidden Valley this weekend, checking in on the progress of his family’s team.