All Blacks lock Scott Barrett has been hit with a three week ban following his red card against the Wallabies on Saturday.

Barrett, who pleaded guilty, trained with the squad this morning, with no additional locking cover brought into the All Blacks squad.

He will miss this weekend's test against Australia but will be free to play in the All Blacks' final warm-up test against Tonga on September 7.

French referee Jerome Garces, who also sent off Sonny Bill Williams in 2017, gave Barrett a red card after a no arm tackle on Wallabies skipper Michael Hooper. His elbow connected the back of Hooper's head.

Cyril Brownlie, Colin Meads and Williams are the only previous All Blacks to be sent off in a test.

"For me I have a clear picture on the field," Garces told the television match official.

"He never uses his arm. He just puts his shoulder and elbow on the neck and head so it's clearly dangerous. It's direct with force so I have no option but to be a red card against four," he added.

The All Blacks lost the test by a record margin - 47-26.

The SANZAAR Foul Play Review Committee of Adam Casselden SC (Chairman), Stefan Terblanche and Eroni Clarke assessed the case.

In his finding, Foul Play Review Committee Chairman Adam Casselden SC ruled the following:

"Having conducted a detailed review of all the available evidence, including all camera angles and additional evidence, including submissions from his legal representative, Stephen Cottrell, the Foul Play Review Committee upheld the Red Card under Law 9.16." 

"With respect to sanction the Foul Play Review Committee deemed the act of foul play merited a mid-range entry point of 6 weeks due to World Rugby instructions that dictate any incident of foul play which results in contact with the head and/or neck must start at a mid-range level. However, taking into account mitigating factors including the Player's exemplary judicial record, his expressed remorse and the fact the Player has pleaded guilty at the first available opportunity, the Foul Play Review Committee reduced the suspension to 3 weeks."

"The Foul Play Review Committee adjourned the hearing to seek more evidence regarding the Player's proposed schedule of matches. Upon reconvening the Foul Play Review Committee was presented with extensive evidence demonstrating the Player's intended playing schedule."

"The player is therefore suspended for 3 weeks, up to and including Sunday 1 September 2019."