Winger Paddy McCourt has been ruled out of their opening double-header against Russia and Luxembourg, while Martin Paterson (hamstring) and Shane Ferguson (groin) will miss the initial trip to the Russian capital.
The latter duo could, however, return for the Luxembourg match at Windsor Park next Tuesday.
"The players will remain with their clubs and will be assessed later in the week ahead of Northern Ireland's home game against Luxembourg on Tuesday (September 11)," a statement from the Irish Football Association read.
Manager Michael O'Neill, who will take charge of his first competitive game on Friday, has not named any replacements.
Source: PA
Source: PA