The 33-year-old came off the bench during the second half to find the net and help his new side record a 2-0 victory over Millwall at Oakwell.
"Jason played his part. But I'm more excited about his quality on the ball, his passing, his movement - [he was] brilliant," said Flitcroft. "His finish was exquisite, but I look at his all-round game, his intelligence, runs and link-up play and he said to me before the game: 'Don't worry about me Flick, I've got an unbelievable touch and my movement is great.'
"I've only known him 24 hours, but there's already an excitement round him and a calmness and I look forward to working with him because he might have found a home here."
Scotland joined the Tykes earlier this week on a free transfer following his release by Ipswich Town.