The 21-year-old, who suffered a slight hamstring injury, has passed a fitness test and will be able to fill the number 10 shirt on Saturday.
Team manager Mick Kearney also revealed that the third vacancy in the squad announced earlier this week will be taken by Munster prop Stephen Archer.
Ireland were shocked by Scotland in their previous Six Nations clash, a disappointing 12-8 defeat at Murrayfield, but could still restore some pride with victory at the Aviva.
The game kicks off at 5pm.
Ireland squad: R Kearney (Leinster); F McFadden (Leinster), B O'Driscoll (Leinster), L Marshall (Ulster), K Earls (Munster); P Jackson (Ulster), C Murray (Munster); C Healy (Leinster), R Best (Ulster), M Ross (Leinster), M McCarthy (Connacht), D Ryan (Munster), P O'Mahony (Munster), S O'Brien (Leinster), J Heaslip (Leinster, capt).
Replacements: S Cronin (Leinster), D Kilcoyne (Munster), S Archer (Munster), D O'Callaghan (Munster), I Henderson (Ulster), E Reddan (Leinster), I Madigan (Leinster), L Fitzgerald (Leinster).