Troy Parrott will be out of action until after Christmas after suffering an injury last Saturday.
The Dubliner went down clutching his hamstring as he celebrated his first goal for Preston North End in the Championship - his 80th minute winner against Norwich City after coming off the bench.
Tottenham loanee Parrott, 20, started the recent Nations League games against Scotland and Armenia but will now miss Ireland's friendlies against Norway and Malta in November.
