The 27-year-old was closing in on a playing return after surgery when an infection forced a second operation on the same shoulder.

O’Brien could yet face the Saxons in Cork on Friday night, while Ireland remain confident both Conor Murray and Eoin Reddan will be fit to open the Six Nations in Italy on February 7.

“Sean trained fully today, trained last week in Leinster and has taken part in all the sessions,” said Irish Wolfhounds coach Richie Murphy.

“There is a possibility that he will be available this week.”

While flanker O’Brien could still feature in Cork, his Leinster team-mate Cian Healy’s chances now appear remote.

The destructive loosehead prop has battled hamstring problems since September, but like O’Brien, is targeting a Test return during the Six Nations.

British and Irish Lions scrum-half Murray continues to battle disc problems in his neck, but Ireland’s skills coach Murphy still tipped him to feature at the Stadio Flaminio on Saturday week.

Leinster half-back Reddan damaged knee ligaments in Saturday’s 20-20 Champions Cup draw at Wasps, but Ireland bosses now believe his injury is not as severe as anticipated.

“Both guys look like they’ll be fit,” said Murphy of Murray and Reddan’s chances of facing Italy.

“Eoin’s knee injury is not as bad as first feared, in the last 24 hours he’s seen a massive improvement.

“We are hoping that both of those guys will be ready for next week and if they’re not it opens up an opportunity for Isaac Boss and Kieron Marmion to come in.

“Cian (Healy is a little further behind Sean (O’Brien), but is doing pretty well.”

Murphy revealed Ireland expect Lions fly-half Johnny Sexton to be available for the second round of Six Nations action against France in Dublin on February 14.

Sexton is forced to sit out the Italy clash while he completes a 12-week stand-down period enforced by club Racing Metro after four concussions in 12 months.

Sexton’s absence leaves Leinster’s Ian Madigan and Munster’s Ian Keatley vying for the starting berth in Rome, with Paddy Jackson also sidelined after elbow surgery.

Murphy hinted that Madigan may be handed the fly-half reins for Friday’s Wolfhounds match, having featured mainly at centre for Leinster this term.

“He is very nearly ready to go,” said Murphy of Sexton.

“Obviously he picked up that injury in France so his club looked after that.

“He’s not taking contacts, he can’t take contact until the three months is up and that would be the week of the French match.

“Until that time it looks like he is going to be out, but he trained today, did all the handling stuff, all the non-contact training and all the fitness work, so he’s looking very fit and very fresh.

“You’d fancy that because he’s been doing all the handling, all the kicking, all that kind of stuff, the contact stuff will fall into place that week.”

Murphy admitted Madigan not featuring regularly at fly-half is “definitely an issue” for Ireland head coach Joe Schmidt.

The 25-year-old may now start at 10 against the Saxons to ease him through to the Six Nations opener in Rome.

“It’s definitely an issue,” said Murphy of Madigan’s limited club time at fly-half.

“When he has played there this year he has been pretty good.

“Joe (Schmidt) will have to make a decision on that later in the week.

“The Saxons match might be an opportunity for Ian Madigan to get a little bit of game time at 10.

“Ian Keatley has played loads of rugby at 10; we kind of know where he is.”