Reds centre-back thrilled with the side's performance as they secure their third Championship win in four!
Barnsley defender Angus MacDonald feels this afternoon's three points against the Millers could be one of the most crucial in the Reds' season.
Adam Armstrong's goal 20 minutes from time proved the difference between the two sides as the Reds moved to within one point of the top six.
He felt that securing back-to-back Yorkshire derby victories could spur the side on further as they bid for a second consecutive promotion.
He said: "It was a massive three points for us, especially after beating Leeds and backing that up with another great result here today.
"The lads you could see from minute one were out there battling and all for the three points.
"Overall, it was always going to be scrappy in parts. Coming into a local derby, everyone wants to do well and pick up three points, especially Rotherham, given they aren't doing so well this season.
"They're out there battling and I'm sure they'll pick up something soon."
Following last weekend's clash with Leeds United, MacDonald was thrilled with the performance the Reds produced to follow on from last weekend's result.
He was also impressed with the contribution of debutant Matty James, who dictated the tempo of the game by sitting just ahead of the defence.
"It was another test just like Leeds was but the lads stuck at it and got the result.
"We had players out there that were playing their first 90 minutes in a long time and they need that cheering on sometimes.
"But credit to 'Jamo' (Matty James) in midfield, he's done well today. "He'll have a fun day I'm sure tomorrow. But it's credit to himself because he did well," he added.
Arriving in the summer, the defender has quickly become a regular in the Reds side and feels they have been putting together a strong run of Championship results recently.
He insists there is no reason why they cannot continue to push on and make it back-to-back promotions for the Reds.
"Normally a side could fall away after Christmas but it's still tight up there and we're still pushing to get into the play-off spots.
"You've seen the past two results, back-to-back derbies and picking up six points is massive for us, you can see the hunger from the lads and even the fans and the coaching staff.
"They want to be back in the Premier League," he added.