The 24-year-old now faces a spell on the treatment table after being substituted after 37 minutes into the 2-1 win against QPR in midweek.
Gabriel was playing just his third game for the north Londoners since making his ??11m move from Villarreal in January.
He is now set to miss Monday’s FA Cup quarter-final clash with Manchester United at Old Trafford, as well as upcoming games against West Ham and their crunch Champions League last-16 second leg showdown against Monaco in France.
“Gabriel has a little hamstring injury and will be out for two to three weeks which means he’s not available for the weekend, West Ham and Monaco, but after that he should be back,” Wenger said.
“Nacho Monreal (back strain) might come back in to the squad. He will have a test today but everybody else should be available from the same squad that played against Queen’s Park Rangers.”
The Sao Paulo-born player made his Gunners debut in the home win over Middlesbrough in the fifth round of the FA Cup and impressed in the recent 2-0 victory over Everton.
The centre-back joins Jack Wilshere, Mathieu Flamini, Mikel Arteta, Mathieu Debuchy and Abou Diaby on the sidelines.