Weir has been forced to play second fiddle to Ruaridh Jackson in Scotland's opening three games, coming off the bench in the victory over Ireland last weekend.
The 21-year-old took his chance to show his class after returning to Glasgow Warriors during the rest weekend, crossing for a try and kicking three conversions and a penalty.
His contribution helped take the Warriors top of the table with a 29-13 victory over Cardiff Blues and gives Scotland interim coach Scott Johnson a welcome selection headache before the visit of Wales next Sunday.
However Johnson has been backed by current All Blacks coach Steve Hansen, who he worked with at Wales, to make a success of his current role.
"He is probably in the top three analysts of the game that I have ever come across," said Hansen.
"He understands back play and we had a team at that point that needed to be coached a lot and needed to be given self-belief - and he was good at that.
"He had a sense of humour, so he didn't take himself too seriously. And he was good at engendering self-belief in the team. He had great people skills."