Chris Paterson replaces Hugo Southwell at full-back, one of two definite changes from the team which beat Italy just over a week ago.
The other sees Alasdair Dickinson replace fellow prop Allan Jacobsen, who underwent shoulder surgery last week and will be out for up to four months.
Dickinson started at tighthead in France but will play on the opposite side of the scrum this weekend.
There could also be changes in the second row, with Hadden naming four players as possible selections for the two spots.
Jason White and Alastair Kellock - who both started against Italy - could be replaced by one or both of the fit-again Jim Hamilton and Nathan Hines.
Hamilton has shaken off the shoulder injury he sustained against France last month.
Hines has yet to feature in the tournament due to a serious knee injury but he has made a quicker-than-expected recovery.
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."
Hadden added: "We're not apologetic about not naming the team today.
"It's not as if it's subterfuge or trying to pull the wool over anybody's eyes, but I'm not too unhappy that Ireland don't know what the second row's going to be.
"We are putting Nathan Hines and Jim Hamilton through a fairly strenuous couple of days.
"We're hoping to make the decision tonight as the result of what we see today but we may have to wait for a doctor's opinion tomorrow (Wednesday) morning.
"We were happy with what Jason and Al Kellock did against Italy and we think we would be happy for them to play against Ireland.
"But we've got two very experienced international players who are back in the mix and we need to have a closer look at them before we consider them available for selection."
Hadden has also delayed finalising his substitutes for the game, with back-three star Rory Lamont making a surprise recovery from the ankle ligament damage he suffered in December.
The one definite change from the 22 for the Italy game sees Glasgow prop Moray Low provide back-up to Dickinson and Euan Murray.
Southwell drops to the bench, with Lamont, flanker Kelly Brown, centre Nick De Luca and one of Hadden's pool of locks looking set to compete for the final two spots.
"Once we have finalised the lock selections, we will complete our bench selection," Hadden said.
"Here, we are also monitoring the welcome return to fitness of Rory Lamont."
Scotland
15 Chris Paterson (Edinburgh)
14 Simon Danielli (Ulster)
13 Max Evans (Glasgow Warriors)
12 Graeme Morrison (Glasgow Warriors)
11 Thom Evans (Glasgow Warriors)
10 Phil Godman (Edinburgh)
9 Mike Blair (Edinburgh) CAPTAIN
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)
Substitutes
16 Dougie Hall (Glasgow Warriors)
17 Moray Low (Glasgow Warriors)
18 TBC
19 Scott Gray (Northampton Saints)
20 Chris Cusiter (Perpignan)
21 TBC
22 Hugo Southwell (Edinburgh)
Referee: Jonathan Kaplan (South Africa). Touch-judges: Wayne Barnes (England) and Carlo Damasco (Italy). TMO: Hugh Watkins (Wales)