A wide barrier has prompted Gary Portelli to scratch Testashadow from the Australian Guineas on Saturday.

Portelli only decided to accept for the Flemington feature following Testashadow's work on Tuesday morning but he was flattened by the draw in gate 16.

"I thought we were on track after his work and we thought we'd have a crack at it," Portelli said.

"Then barrier 16 came out and I was still trying to find excuses to run.

"It's a Group One with an expensive scratching fee but every time I came up with where we'd get to in the run, my gut feeling was overwhelming and that was `just don't do it to the horse with the long trip down'."

Portelli said the more he looked at the race, the more he realised Testashadow would be forced to go right back from the draw.

He said at that level and against that class of horse the task was too great.

"It could have been worse, it could have been for a reason rather than the barrier," Portelli said of the scratching.

Testashadow will now stay in Sydney and head to the Phar Lap Stakes (1500m) at Rosehill on Saturday week.