Conor Murray has been ruled out of the remainder of Ireland's autumn series due to a groin injury but there were positive updates on a number of key players including captain Johnny Sexton.
Murray, who became Ireland’s eighth centurion against South Africa on Saturday, suffered the injury when making a line break during the first half of the 19-16 win.
The scrum-half has returned to Munster to begin his rehabilitation.
Murray’s half-back partner Sexton is "recovering well" after he sustained a dead leg against the Springboks but the IRFU did not reveal if he will take part in training this week.
Tadhg Furlong and Stuart McCloskey suffered arm and ankle injuries respectively during an attritional game against the world champions but they are not as serious as first feared and could be available for Saturday’s game against Fiji.
McCloskey will train with the squad while Furlong is expected to take part in preparations for Ireland’s second Bank of Ireland Nations Series fixture.
Henshaw will also be reintegrated into training after his late withdrawal from the South Africa game with a hamstring issue.
Ireland head coach Andy Farrell has named a 39-player squad which includes Ulster forward Iain Henderson, who has yet to feature this season due to injury.
Munster out-half Jack Crowley is promoted to the senior squad along with Caolin Blade, Max Deegan, Scott Penny and Gavin Thornbury, with all five having played for Ireland 'A' against an All Blacks XV.
Gavin Coombes drops out of the squad along with Munster team-mates Diarmuid Barron, Dave Kilcoyne, Shane Daly. All four could come into contention for Thursday's game against South Africa 'A' at Páirc Uí Chaoimh.
Leinster trio Ciarán Frawley, Joe McCarthy and Ryan Baird have returned to their province. Frawley twisted his knee while playing for Ireland 'A’ while McCarthy and Baird have entered the head injury return-to-play protocols.
Leinster prop Michael Milne, who featured for Emerging Ireland in their wins over the Pumas and Cheetahs, will train with the Ireland squad this week.
Backs (16): Robert Baloucoune, Caolin Blade, Joey Carbery, Craig Casey, Jack Crowley, Jamison Gibson-Park, Mack Hansen, Robbie Henshaw, Hugo Keenan, Michael Lowry, Stuart McCloskey, Calvin Nash, Jimmy O'Brien, Garry Ringrose, Johnny Sexton (capt), Jacob Stockdale.
Forwards (23): Finlay Bealham, Tadhg Beirne, Jack Conan, Max Deegan, Caelan Doris, Tadhg Furlong, Dave Heffernan, Cian Healy, Iain Henderson, Rob Herring, Jeremy Loughman, Michael Milne, Peter O'Mahony, Tom O'Toole, Scott Penny, Andrew Porter, Cian Prendergast, James Ryan, Dan Sheehan, Gavin Thornbury, Nick Timoney, Kieran Treadwell, Josh van der Flier.