The West Ham goalkeeper will replace Sunderland shot-stopper Kieren Westwood, who has withdrawn from the squad and returns to his club
The Hammers goalkeeper will replace Sunderland goalkeeper Keiren Westwood, who has returned to his club. Henderson will join up with the rest of the squad for training in Craven Cottage today.
The 24-year-old has been capped at youth level for the Republic of Ireland but has yet to receive his first senior cap.
A former Aston Villa and Portsmouth custodian, Henderson received his first call up by Giovanni Trapattoni in February 2012, when he was included in the squad for the friendly game against the Czech Republic.
Meanwhile, Sean St Ledger left yesterday's training session with a leg injury, while Aiden McGeady was granted an extra day's rest.
Giovanni Trapattoni's Republic of Ireland face Oman in a friendly fixture at Craven Cottage on Tuesday September 11.