The stand-off returns to the Glasgow No.10 shirt in Cardiff tonight after his successful second-half Scotland cameo against Ireland in last Sunday's Six Nations victory.
Weir is determined to play a key part in taking Warriors' winning league run to seven games in the final fixture before a three-week break that proceeds the final five games of the regulation season.
With Glasgow sitting pretty in second place, just two points behind leaders Ulster, he is determined to keep up momentum.
He said: "It has got to be one game at a time and there is an awful lot of rugby still to be played against really good quality opposition.
"But we are sitting second right now and the target has got to be to stay there and claim the home semi-final that will accompany a top two place.
"We have set and maintained a very high standard in recent weeks and it is vital that we maintain it against the Blues.
"To have taken five points from the visit of Ulster last week was massive and there can be no falling off that level tonight.
"But we are under no illusion as to how tough that will be given that Cardiff have beaten Munster and Edinburgh in their last couple of away games.
"We can't let our focus wander down the track. We have to stay absolutely focused on taking maximum points tonight and going into the break with our momentum well and truly intact and also keeping the pressure on Ulster."
Weir will face a battle of the boot with outstanding young Welsh fly-half Rhys Patchell and is determined to keep the Blues playmaker guessing in the game of cat and mouse that is likely to develop between the two from 7.35pm.
The Warriors ace said: "Patchell has made a tremendous impact for Cardiff considering he is only 19 and it will be up to me to make sure he is second guessing and finding himself enveloped in as many tackles as possible.
"It wasn't that long ago I was in a similar position at a similar age to Rhys so it will be interesting to pit my wits against a new kid on the block like him."
He added: "I am looking forward to partnering Niko (Matawalu) in the half-back pairing.
"Niko was tremendous against Ulster last week and I am excited about playing alongside him. But on a personal note it is just great to be getting the start after my Scotland involvement.
"I felt I had a decent game against the Dragons a couple of weeks back and I am just looking to improve every time I take the field.
"I felt like what I did for Scotland was a positive step on from the Dragons game for Glasgow. Now I have the chance to take things on again tonight against the Blues against an opponent in Patchell who will really test me."
Warriors' superlative work at the breakdown last time out against Ulster secured quick ball for a rampant backline – Matawalu in particular – to play the most scintillating rugby seen at Scotstoun this season.
Weir is determined for a repeat and said: "Ulster tend to wreak havoc at the breakdown but our accuracy was immense and the quality of quick ball we produced from it allowed us to play at a tempo that was a joy to watch.
"We have to be looking to repeat that tonight and make sure there are no slip-ups."
Meantime, Scotland under-20 star Mark Bennett has signed a new one-year deal.