Marshall facing sideline spell as precaution after head injury
Luke Marshall's prior history with concussion means he is being treated as a special case by the Irish medical team as they look to protect the Ulster centre from further injury.
The 23-year-old came off 16 minutes into the second-half of Saturday's first Test win over Argentina with a suspected head injury but tests carried out since revealed he was not concussed.
He is being assessed daily, having passed the tests carried out in the aftermath of the game and further neurocognitive tests on Sunday.
Marshall was stood down from the end of last season after suffering three concussions in a short space of time and he suffered another in March.
"That's why we'd be very careful with Luke," Ireland manager Mick Kearney said yesterday. "He did suffer a number of concussions in a relatively short period of time and got one earlier this year as well, so that's why we are taking every precaution."
Indications are that all 29 players who travelled to Argentina will get some involvement in the Test series, so coach Joe Schmidt is likely to give Marshall the week off.
That could mean a first cap for Noel Reid at inside centre, while the Kiwi could also shift Darren Cave to No 12 and play Fergus McFadden outside him, with Ian Madigan also an option.
A dead leg will rule Conor Murray out of training today which could see Eoin Reddan step into the scrum-half slot, although Kieran Marmion impressed last week.
James Cronin and Robbie Diack will hope to start, although it is hard to see Jack McGrath and Rory Best losing out so Dave Kilcoyne and Damien Varley may give way.
Rob Kearney, Jamie Heaslip and Devin Toner are likely to come into the team ahead of Felix Jones, Jordi Murphy and Iain Henderson, while Rhys Ruddock will be hoping to displace Diack.
The Irish squad make their way to the city of Tucuman tonight ahead of Saturday's second Test.
And they are in for something of a rude awakening at the Estadio José Fierro.
"The changing area in Tucuman is like something out of a badly run down club from the 1970s," Kearney said. "It will be a little bit of a challenge, but Tucuman is in the heartland of Argentinian rugby so I'd expect a good crowd, very passionate."