McKay has been called up to the Scotland U21 squad to face Ukraine next Friday in a European qualifier.
“I know when he came with the 19s he was a very energetic player,” Sbragia told Herald Scotland. “He always performed at a high level for us so in general I think he’d be loving it now.
“The manager loves him, he’s done extremely well and he’s playing week in week out. He’s playing some really good football and that can only be good for Barrie.”
McKay, who has been at Rangers his entire professional career so far, has established himself as an important player for the Gers this season.
The 20-year-old winger has featured in as many as 18 competitive matches for Mark Warburton’s side.
The exciting youngster has impressed with his performances on the flanks, and he has shown his potential.
Rangers are at the top of the Scottish Championship table at the moment with 33 points from 12 matches, five points clear of second-place Hibernian.
The Gers will take on Alloa Athletic at Ibrox in Glasgow in the league on Saturday afternoon.
Warburton’s side will head into the encounter on the back of a 2-1 defeat to Hibernian away from home at Easter Road in the Scottish Championship.