Lienert-Brown was found guilty of dangerous contact in a ruck. He was yellow-carded for a reckless cleanout in the 59th minute of the match at Forsyth Barr Stadium in Dunedin on Saturday night.
It was later upgraded to a red card by the TMO.
Despite being down to just 13 players at one stage the Highlanders managed to hold on to beat the Blues 29-21.
The judicial committee ruled the act of foul play merited a mid-range entry point of six weeks/matches.
Lienert-Brown accepted he committed an act of foul play and along with mitigating factors such as his disciplinary record, remorse and conduct, the judicial committee applied the full 50% reduction in sanction.
The 32-year-old was also given permission to apply to take part in World Rugby's coaching intervention programme as a substitute for the final match of the sanction.
He will miss the Super Rugby Pacific matches against Moana Pasifika, the Hurricanes and the Queensland Reds.
