The 20-year-old headed Israel level at 1-1 in the 55th minute at the Raiffeisen Arena, cancelling out Romano Schmid’s first-half penalty. He then ran to the corner, pulled out the flag, dropped to one knee and made a firing gesture with the pole.
Referee Georgi Kabakov showed Abu Farchi a second yellow card, four minutes after his first booking, and then a red. Israel were left with 10 players.
Under IFAB Law 12, players may celebrate a goal but must not do so in a provocative, derisory or inflammatory way. Excessive or inflammatory celebrations can be cautioned.
Austria went on to win 3-1. Phillipp Mwene restored the lead in the 90th minute from a Paul Wanner cross, and Sasa Kalajdzic added a third in stoppage time.
Abu Farchi plays club football for Colorado Rapids in Major League Soccer. Israel manager Ran Ben-Shimon said after the match that the forward has used a similar celebration at club level without being booked. Some observers suggested the motion resembled a pool-cue shot; the referee treated it as an inflammatory celebration.
The fixture took place against a tense political backdrop. Austria fans displayed a “Free Palestine” banner near the pitch. Israel’s presence in the Nations League has drawn protest from several associations, including the Republic of Ireland, whose request not to be paired with Israel was rejected by UEFA.
Ireland face Israel on Sunday at a neutral venue, the Nagyerdei Stadion in Debrecen, Hungary, before hosting the return fixture on 4 October.
Al Jazeera said it had contacted UEFA and Colorado Rapids for comment on the celebration. Austria take the three points from the Group G opener; Israel must regroup without their young forward for at least the next competitive fixture.