David Wallace, Geordan Murphy and Simon Best missed Ireland squad training on the first full day of the pre-World Cup camp in south west France on Tuesday.
Geordan Murphy sustained a dead leg against Scotland
Wallace has an ankle injury while Best is continuing to be troubled by the back spasm that affected him prior to Saturday's game against Scotland.
Murphy sustained a dead leg in the 31-21 defeat where he produced a fine display to secure his World Cup place.
The Ireland players trained in temperatures of 28 degrees on Tuesday.
The squad's warm weather camp is taking place at Capbreton in South West France.
The French trip also includes a warm-up game against French club Bayonne on Thursday which is reportedly a 15,000 sell-out.
"I would expect to get as many of the players who did not feature against Scotland on the park at some stage," said Ireland coach Eddie O'Sullivan of Thursday's game.
"Teams in this part of the world take their rugby very seriously and in front of what is expected to be a full house, we expect to get a tough game."
Ireland centre Gordon D'Arcy said the training camp is an important part of the squad's World Cup build-up.
"It's great to be able to train in these sorts of conditions as it gives us the chance to get a lot or work done without worrying about rain or the weather affecting what we do," said D'Arcy.
"The session was full on and guys are very keen to be involved in the game on Thursday. For a lot of us it may be our first hit out of the season, so the intensity was really high."