The 24-year-old Brazilian defender was forced off in the 36th minute of the game at Loftus Road. It was only his third start for the Gunners.
Gabriel, who was signed from Villarreal for a reported £11m in January, will miss Arsenal's FA Cup sixth-round tie at Manchester United on Monday, a game that Wenger says has a "special intensity".
"It's a special intensity because it's between two teams with a chance of winning," the Frenchman said. "We're focused on the FA Cup.
QPR 1 Arsenal 2 player ratings
QPR 1 Arsenal 2 player ratings
1/22 Rob Green 6
Put under pressure much more in the second half. Difficult to criticise him for the two Arsenal. If it wasn’t for him the difference between the sides would have been greater. A strong save to deny Ozil late on.
2/22 Suk-Young Yun 5
A danger for Bellerin in the early stages of the game but the Arsenal right back soon worked out what he was trying to do - take advantage of the overlap. Aimless balls forward meant the opposition were able to regroup quickly.
3/22 Nedum Onuoha 5
Clashed heads with Caulker towards the end of the first half. He was replaced by Clint Hill minutes before half-time due to injury.
4/22 Steven Caulker 5
Effective at defending Arsenal corners. Though he was sloppy when put under pressure by Sanchez and Giroud.
5/22 Darnell Furlong 5
Similar to Yun, he chose to push forward and attack the right flank. Very good range of passing too. Defensively, though, he was poor. That was proven when Sanchez easily skipped past him before scoring Arsenal’s second.
6/22 Matt Phillips 7
A constant threat on the right side of the QPR midfield. His powerful volley from 25 yards on the hour would have been a contender for goal of the season had it crashed into Ospina’s net. Provided the assist for Austin’s goal.
7/22 Karl Henry 4
Often went missing in midfield. Too many misplaced passes from him meant QPR’s attack broke down quickly.
8/22 Sandro 6
Did well on his return back from a knee injury. Looked to progress play where possible and fed Austin particularly well. Tired in the second half and was replaced by Niko Kranjcar on 56 minutes.
9/22 Junior Hoilett 7
Did well to track back and defend. Stayed close to Rosicky. Always a threat when he got near the Gunners’ penalty area. He was replaced by Mauricio Isla on 73 minutes.
10/22 Charlie Austin 7
Threatened the Arsenal defence early on. He wasn’t afraid to shoot either. His goal late on that gave QPR brief hope of getting a point was brilliant.
11/22 Bobby Zamora 6
Demonstrated why he can still make an impact in the Premier League even if he did start to tire shortly after half-time.
12/22 David Ospina 6
Relatively comfortable evening. Austin’s shots on target were in the centre of his goal and didn’t trouble the goalkeeper. Beaten by a beautiful effort by the striker - may have done a little better.
13/22 Hector Bellerin 6
Got the better of Yun on the left side of the QPR defence numerous times. He was allowed plenty of space on the overlap but his final ball was often poor.
14/22 Per Mertesacker 6
Back in central defence after he was on the substitutes’ bench against Everton. He did well against the physical Zamora.
15/22 Gabriel Paulista 5
Struggled with the presence of Zamora. He was replaced on 36 minutes by Laurent Koscielny due to injury.
16/22 Kieran Gibbs 7
Linked up very well with Sanchez in the second half. His penetrating runs down the left made it difficult for Furlong.
17/22 Tomas Rosicky 6
Misplaced pass. Marked well by Hoilett. His creativity was stifled in the first half but in the second he found a slightly better range of passing.
2015 Getty Images
18/22 Francis Coquelin 6
His first match since sustaining a broken nose in the home win against Everton. The game seemed to bypass him at times.
19/22 Santi Cazorla 7
His usual skillful self. He started alongside Coquelin in the deep-lying playmaker position but it was only when he drove forward that he was effective.
20/22 Mesut Ozil 7
Started the attack that led to Arsenal’s opening goal. Positioned behind Giroud, the German became more important as the game wore on.
21/22 Olivier Giroud 7
Not particularly convincing in the first half. He chose more often than not to fire aimlessly from outside the area. That changed in the second half. His goal set Arsenal on their way.
22/22 Alexis Sanchez 8
More of a threat in the second half as he started to cut in from the left. Roamed all over Arsenal’s attack. He should have scored when he was one-on-one with Green. Redeemed himself when he doubled his side’s lead on 70 minutes after skillful play.
"We are the holders of the FA Cup and we want to keep it. The cup is about giving it all on the day and we'll do that on Monday.
"We are confident. We go to Manchester United to qualify and give absolutely everything with hard work and team effort."
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