The other change sees Alasdair Dickinson introduced at loosehead prop instead of the injured Allan Jacobsen.
Dickinson was on the opposite side of the scrum earlier in the Championship when Scotland played against France in Paris.
Scotland coach Frank Hadden may make further changes. Four second row forwards have been bracketed for the two lock starting positions.
Jason White, who played for his club on Sunday, and Alastair Kellock, who trained yesterday after the ankle injury he sustained against Italy, are in contention for the lock berths.
As are Jim Hamilton (restored to fitness after the shoulder problem he suffered against France last month) and Nathan Hines, who is also available for selection after extensive work with Scotland's rehab physiotherapists to recover from a knee problem which has kept him sidelined since January.
Scotland coach Hadden said: "It will be a close call in the second row but clearly we'll go with the players we believe give us the best chance of creating the sort of platform that we'll need to win against a fine Irish team.
"I've been impressed with Chris Paterson's attitude in this Championship. As ever, he's been the model professional, getting on with his job and he deserves the opportunity to start on this occasion.
"Once we have finalised the lock selections we will complete our bench selection. Here, we are also monitoring the welcome return to fitness of Rory Lamont."
SCOTLAND TEAM & REPLACEMENTS (v Ireland, 2009 RBS 6 Nations Championship, Murrayfield, Saturday, March 14, kick-off 5pm):
15 - Chris Paterson (Edinburgh)
14 - Simon Danielli (Ulster)
13 - Max Evans (Glasgow Warriors)
12 - Graeme Morrison (Glasgow Warriors)
10 - Phil Godman (Edinburgh)
9 - Mike Blair (Edinburgh) (capt)
1 - Alasdair Dickinson (Gloucester)
2 - Ross Ford (Edinburgh)
3 - Euan Murray (Northampton Saints)
Locks (4/5) from: Jim Hamilton (Edinburgh), Nathan Hines (Perpignan), Alastair Kellock (Glasgow Warriors) and Jason White (Sale Sharks)
6 - Alasdair Strokosch (Gloucester)
7 - John Barclay (Glasgow Warriors)
8 - Simon Taylor (Stade Francais)
16 - Dougie Hall (Glasgow Warriors)
17 - Moray Low (Glasgow Warriors)
18 - to be confirmed
19 - Scott Gray (Northampton Saints)
20 - Chris Cusiter (Perpignan)
21 - to be confirmed
22 - Hugo Southwell (Edinburgh)