Cardiff manager Neil Harris confirmed Lee Tomlin is set for another spell on the sidelines after celebrating his side's first home victory of the season.
An early strike from Junior Hoilett and Joe Ralls' third goal in two games had them coasting to victory before a Harry Wilson wonder-strike wrapped up the 3-0 victory.
The vital three points lifted the pressure on Harris and boosted the Bluebirds to within four points of the play-offs.
But the comprehensive victory was tarnished by the news of Lee Tomlin's ongoing groin issue that will see him miss Friday's Severnside derby clash against Bristol City.
"Lee wasn't fit. It doesn't look like he is going to be fit for Friday or the coming weeks so we'll have to see what unfolds daily with Lee Tomlin," Harris said.
"It's just issues with the groin from playing just under 30 minutes the other day. Obviously with Lee Tomlin not available to us now, we saw the importance of Robert Glatzel and Harry Wilson, two more players that can link the play and change the game in a moment.
"I can talk a lot about the goals we scored, the chances we created, the clean sheet, but I am most impressed with the reaction of my players.
"Obviously I was honest in my opinion after the game on the performance in the first half at QPR. I was honest with my players at half-time and after the game.
"When you do that you want a positive reaction from the group and tonight I got that.
"I thought the performance level tonight individually and collectively was outstanding. The only frustration is that we didn't score more."
The defeat in the Welsh capital was new Barnsley manager Valerien Ismael's first taste of defeat since taking over last month.
His side are now only four points above the relegation zone despite winning his first two games in charge.
"I was disappointed with the defending for the goals today," said Ismael.
"In the first half we could have had a penalty with Patrick Schmidt and then on the counter-attack we conceded a penalty, which was also a penalty, and that changed the game. We didn't do enough after 90 minutes.
"A lot of things went wrong today, tiredness was an issue and we had injuries which forced us to change the formation.
"Today it was very difficult because we weren't dangerous enough in the opponent's box and we didn't create enough opportunities in their box to score.
"We have to analyse why it was like this today and put it right for the game against Derby on Saturday.
"We saw today in the first half, it was very difficult, it was better when Victor Adeboyejo came on and I hope we can get Cauley Woodrow back soon because we need a physical striker for the next game. We have to adapt for the future and learn."
