Rory will likely have to settle for second Best with place on bench
The very reason Jamie Heaslip was passed last week over is the reason Rory Best probably won't play this week.
Although the Ireland number eight was fit for purpose by last Thursday, Ireland coach Joe Schmidt decided to go with Jordi Murphy because he had been running there in the lead into the game.
Schmidt tends to have his starting side nailed down and preparing by Tuesday.
"Best's concussion means the Ulster hooker's best case scenario is that he will be available to train fully on Thursday.
Too late for Heaslip last week; too late for Best this week.
Anyway, Best has to engage in the return-to-play protocols from concussion at a very sensitive time around that issue.
A n MRI scan hs revealed what Team Manager Mick Kearney called "a hamstring strain on the minor end of the scale" for Sean O'Brien.
However, he must be strong odds against making the deadline, even though he has been cleared to train tomorrow.
On a more positive note, out-half Jonathan Sexton, Heaslip, prop Cian Healy, scrum-half Eoin Reddan and wing Dave Kearney have all been declared "fully recovered."
The return of Healy could be considered due to the wilting of the Ireland scrum when the second front row was introduced against Italy in Rome.
The change-up of Reddan could also be a card Schmidt will turn to in what has been his preferred one-two of Conor Murray and the other Limerick man.
There is the sensitive issue over World Rugby's investigation into George North's concussions.
"I know the Welsh medical team are stating they didn't actually see the second knock that he took," said Kearney.
"If you take them at their word there, it was a genuine error on their part."
He rated the same situation happening for Ireland as highly unlikely.
"Looking at the way the Irish medical team is set up, with a physio on the far side of the pitch and two medics on the near side, I would hope we wouldn't miss something like that."