The 2009 Lions pair have been named in their country's second-string line up to face Ireland Wolfhounds at Ulster's Ravenhill on Friday night.
Murray, who was pressing for a Test place in South Africa eight months ago before a leg injury brought his tour to an unfortunate end, has opted out of Scotland's Six Nations opener against France on Sunday due to religious beliefs.
The Northampton Saints prop will therefore look to hone his international match fitness for the A side as they attempt to avenge their only loss of 2009.
The A game will be Murray's first taste of international rugby since the Lions tour after he missed all three November Tests as part of a lengthy recovery process following the injury setback against the Southern Kings on June 16.
Having just signed a two-year contract extension with Edinburgh, scrum-half Blair is in line for his first competitive start since November.
The 28-year-old joint Scotland captain suffered an ankle injury during the autumn win over Fiji and missed the historic win over Australia and the narrow defeat to Argentina, as well as a host of Magners League and Heineken Cup games.
Called up as a pre-tour replacement for injured Ireland No9 Tomas O'Leary, Blair featured in three tour fixtures for Ian McGeechan's Lions, including the tour opener against a Royal XV.
Both he and Murray will hope strong performances lead to a place in the matchday squad for Scotland's second round Six Nations clash with Wales on February 13.
"The players have all bought into what we are trying to achieve and they realise this is a stepping stone towards playing for Scotland in the Six Nations," said Scotland A and Glasgow Warriors coach Sean Lineen.
"Last year, Scotland A enjoyed a huge amount of success - including the Nations Cup triumph in Romania - and only lost one match in 2009.
"Unfortunately that result was against Ireland A, so we are keen to set the record straight and produce a positive performance in Belfast.
"All of the players involved are pushing for selection in the senior team and there is the right balance in the squad with youth and experience."
Scotland A (vs Ireland Wolfhounds, Friday, February 5, Ravenhill, kick off 7.30pm)
15 Jim Thompson (Edinburgh)
14 Nikki Walker (Ospreys)
13 Ben Cairns (Edinburgh)
12 Nick De Luca (Edinburgh)
11 Simon Danielli (Ulster)
10 Ruaridh Jackson (Glasgow Warriors)
9 Mike Blair (captain) (Edinburgh)
1 Jon Welsh (Glasgow Warriors)
2 Dougie Hall (Glasgow Warriors)
3 Euan Murray (Northampton Saints)
4 Scott MacLeod (Edinburgh)
5 Jim Hamilton (Edinburgh)
6 James Eddie (Glasgow Warriors)
7 Roddy Grant (Edinburgh)
8 Scott Gray (Northampton Saints)
16 Andrew Kelly (Edinburgh)
17 Kyle Traynor (Edinburgh)
18 Craig Hamilton (Edinburgh)
19 Fraser McKenzie (Edinburgh)
20 Greig Laidlaw (Edinburgh)
21 Rob Dewey (Glasgow Warriors)
22 John Houston (Edinburgh)