The Pompey winger has been called up to train with Mick McCarthy’s men during their camp in Portugal which begins on May 21.
The panel will then be revised for Ireland’s European Championship 2020 qualifiers with Denmark (June 7) and Gibraltar (June 10).
It’s the second time Curtis has been selected by McCarthy since he over from Martin O’Neill as manager last November.
The former Derry City ace was set to be involved in Eire’s Euros qualifiers against Gibraltar and Georgia in March.
However, he suffered a freak injury when he severed his finger in his front door, forcing him to pull out of McCarthy’s squad.
Curtis won two caps for the Green Army while O’Neill was in charge, coming against Northern Ireland and Denmark/
It’s highly likely the London-born talent would be available to feature for Pompey should they reach the League One play-off final.
Kenny Jackett’s side meet Sunderland in the semi-final, with the first leg at the Stadium of Light on Saturday before the return game takes place at Fratton Park on Thursday, May 16.
Should the Blues prevail through the last four, they’ll return to Wembley for the second time this season on Sunday, May 26.
Pompey would play either Charlton or Doncaster.
Curtis has enjoyed a fine maiden season at Fratton Park since his £100,000 move from Derry City last summer.
He recorded 12 goals and 15 assists to date, while he was named Pompey’s Young Player of the Season.