Irish duo included despite injuries
Cian Healy and Sean O'Brien moved a step closer towards Six Nations action after being named in Ireland's 46-man training squad.
Ireland head coach Joe Schmidt selected the Leinster duo in his wider Six Nations squad despite both still battling long-term injuries.
Schmidt's decision not to send the influential forward pair back to Leinster to continue their recovery increases their chances of turning out for the Irish Wolfhounds' clash with England Saxons on Friday, January 30.
Fit-again Connacht prop Nathan White and Leinster back-rower Jack Conan are the only uncapped members of Schmidt's squad.
"The coaching group have tried to strike a balance between some players getting the chance to fully complete their rehabilitation programmes, or get a bit of rest, and others getting the opportunity to push their claims with further game time in the Wolfhounds fixture," said boss Schmidt.
Injury doubts remain over Johnny Sexton, Conor Murray and Robbie Henshaw, but all three have been included in the extended squad.
Racing Metro fly-half Sexton could miss the first two rounds of fixtures while he completes a 12-week lay-off after suffering four concussions in 12 months.
Munster scrum-half Murray is carrying a disc problem in his neck but the severity of the issue remains unclear, while Henshaw is battling a "low-grade" ankle ligament problem.
Ireland open the defence of their Six Nations title by taking on Italy in Rome on Saturday, February 7, with a host of regular stars missing through injury.
Chris Henry, Paddy Jackson, Stuart Olding, Dan Tuohy and Damien Varley have been excluded from the squad entirely and effectively ruled out of the tournament.
Robin Copeland, Dave Kilcoyne, Luke Marshall, Donncha Ryan and Andrew Trimble have been told to stay with their provinces, but Ireland have reserved the right to bring them back into the squad if and when required.
The decision to retain Healy and O'Brien underlines just how close both men are to making playing returns.
Leinster decided against pitching one or other into action in Saturday's crucial Champions Cup trip to Wasps, before targeting the Pro12 clash against the Dragons on February 15 as a potential return fixture.
Bullish flanker O'Brien has not featured for Ireland since damaging his shoulder in the 24-22 Test defeat to New Zealand in November 2013.
The 27-year-old has had to undergo two successive operations on the same shoulder, but is finally nearing fitness.
Ball-carrying prop Healy suffered a severe hamstring tear in September and has been grafting towards Six Nations fitness ever since.
New Zealand-born prop White was in line to become Ireland's fourth-oldest debutant of all time in the autumn at 33, but ruptured an arm tendon and missed the November series.