Tade has been in good form of late, plundering goals against Kilmarnock and Hearts.
And Tel believes Tade's performance against Celtic means he is settling into life in the SPL with Inverness following his summer arrival from Raith Rovers.
"Gregory missed a lot of pre-season and when he made his debut for us in the opening match against Motherwell, he was probably only 70 per cent fit," Butcher told the Inverness Courier.
"However, at the start of the season I don’t really think Gregory believed that he belonged in the SPL. I think there was a major doubt in his mind.
"But there was certainly no doubt in my mind and over the last few games he’s grown in confidence.
"His mobility, sharpness and understanding of the players around him has improved greatly and that was shown on Saturday when he had a helluva game."