The on-loan Fulham forward, 21, was a Bees villain after he missed a 90th-minute spot-kick against Doncaster on the final day of last season that would have seen them automatically promoted from League One.
But Button said: "That penalty has been talked about quite a lot, but hopefully that is behind him now.
"He showed fantastic character to come back to us.
"He is on a good run. He is a quality player and he shows his quality in training.
"The fans have taken to him now and, hopefully, he can repay them for last year."
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