James Lowe will miss Leinster's crucial Champions Cup tie with Toulouse on January 12 after being given a two-week ban for his red card against Munster.
Lowe was sent off in the 32nd minute of Leinster's 26-17 defeat at Thomond Park on December 29 for a dangerous tackle on Munster's Andrew Conway.
The New Zealander faced a disciplinary hearing via video conference on Thursday and accepted that he had committed an act of foul play which deserved a red card.
A three-person disciplinary committee backed referee Frank Murphy's decision to dismiss Lowe and deemed the act warranted a low-entry point of four weeks.
This was halved due to the 26-year-old's clean disciplinary record and "the conduct of the player and his club throughout the process".
Lowe, who has scored seven tries in 10 appearances this season, will miss Saturday's PRO14 derby against Ulster as well as the crunch European clash with Toulouse seven days later.
He has the right to appeal.
Leinster sit two points behind leaders Toulouse in Pool 1 of the Champions Cup, having lost 28-27 at the Stade Ernest Wallon in round two, but a win in the return fixture at the RDS will put them in pole position to finish top and clinch a home quarter-final.