The deal was revealed by Tykes manager Lee Johnson after watching his side win their opening League One match at Oakwell.
Substitute Conor Hourihane’s penalty gave Barnsley all three points.
The spot-kicks came after Josh Scowen had been brought down in the area by Damien McCrory.
Burton spurned chances to level, Mark Duffy with a glaring miss before Timmy Thiele rattled the bar from long range.
Tykes boss Johnson confirmed after the game that former Manchester City full-back Reece Wabara is joining the club on a short-term deal.
The 25-year-old left South Yorkshire rivals Doncaster at the end of last season.
Burton Albion manager Jimmy Floyd Hasselbaink said: “The boys did well. The first 20 minutes I thought they had it difficult but after that we looked good. We were the better side. Their keeper worked a lot harder than our goalkeeper. I think our goalkeeper didn’t have a save to make in the first half.
“They had a lot of ball possession but they didn’t really create. I think we created a lot more. We get a penalty against and then it’s always difficult because they don’t need to come out. They can keep the ball and make it difficult for us.”