Mike Blair has been in fine form for Edinburgh

Blair, who worked under Hadden at Edinburgh Gunners, will face Argentina at Murrayfield on Saturday, with Lion squad member Cusiter on the bench.

Dan Parks is chosen ahead of Phil Godman at stand-off.

And centre Marcus Di Rollo, hooker Dougie Hall and lock Craig Hamilton will make their home cap debuts.

The trio will be making their first full Scotland appearances at Murrayfield after winning previous caps on foreign soil.

Competition had been intense for Hall, with Glasgow's Scott Lawson and Border Reivers' Ross Ford both in fine form.

Chris wasn't involved in the summer, so he is just beginning to come to terms with the shape of the game I would like to play Frank Hadden

But it is the choice of Blair ahead of Border Reivers' Cusiter that will be biggest talking point among the rugby community.

Blair played in Scotland's summer Test wins over the Barbarians and Romania while Cusiter was involved with the New Zealand-bound Lions.

And Hadden said: "Mike has played exceptionally well and Chris is a fantastic rugby player.

"It is a tight one - it is not a question of someone being better than someone else.

"It just seemed to make a lot of sense to me to have a guy in there who is a very good player, knows exactly what I'm looking for and played in the last game.

"Chris wasn't involved with Scotland in the summer, so he is just beginning to come to terms with the shape of the game I would like to play.

"He is obviously very familiar with the defensive set-up, but there is a bit of learning to do in attack.

"But he is such a good player I'm really confident he will pick it up in next to no time."

"It's pretty evident that Chris' basics are absolutely sensational.

"He's probably slightly stronger than Mike, both are equally strong in defence and their tactical kicking is an area that they both need to work on.

"But, in terms of attack, Mike is obviously more familiar with the things I expect from a scrum-half than Chris is and that's really just about it."

Hadden led Scotland to two victories as interim coach before being chosen as successor to the sacked Matt Williams.

Now he is aiming to build on the success of the three professional teams this season when the Autumn Test series begins.

"Argentina will represent a formidable challenge for us on Saturday," he said.

"They are above us in the IRB world rankings and Scotland have not beaten The Pumas for 15 years.

"But I believe we approach this game in good heart and the fact that our three pro-teams amassed between them another 10-point haul in the Celtic League at the weekend means we can go into the contest with confidence."