Poirot was handed an orange card for a head-on-head tackle in the Top 14 match against Montpellier last weekend.
The LNR, the body that runs professional rugby union in France, announced a two-week ban on Wednesday, which includes matches in the Champions Cup.
Poirot, 33 and an ever-present for the Bordeaux team this season, will also miss the Top 14 match at Bayonne on May 9.
Another absentee for the semi-final is Bordeaux coach Yannick Bru, who will be unable to take his place in the dugout after being punished for "lacking respect for the authority of a match official" during the 23-21 home loss to Montpellier.