Comment: As Ireland's only available Premier League midfielder, Jeff Hendrick must be Martin O'Neill's driving force
After a fortnight that has tested his diplomacy skills and persuasive powers, Martin O'Neill landed in Cardiff last night with football matters on his mind.
For the kick-off of a new competition, Ireland are set to field a team that has played a competitive game together before.
James McClean's injury woe follows on from Declan Rice and Harry Arter's decision to sign themselves out of duty.
O'Neill will at least have familiarity in the defensive area and Seamus Coleman's return adds strength to the department that was a key element of last October's win in Wales.
David Meyler and Jeff Hendrick are the only members of the front six from that victory which are available.
It was Arter's dummy that created McClean's goal. Robbie Brady will be back next month. Daryl Murphy has retired from international duty.
With Shane Long out, Jon Walters is the only travelling player in the squad that fits the description of a central striker. O'Neill likes to use McClean as a support option and that solution is no longer available.
The 66-year-old will have to construct a midfield that is able to deal with a Welsh side that can call on Joe Allen and Aaron Ramsey with Gareth Bale dropping deep to provide another complication.
It's a major worry. Hendrick will definitely play, although O'Neill has grappled with the issue of his deployment since Euro 2016.
On the last visit, he was on the right side of midfield and his bustling presence contributed to McClean's magic moment. Meyler and Arter did a lot of the hard graft in the centre of the park.
However, there were other occasions - most notably at the Aviva - where O'Neill sought to use Hendrick as an advanced attacking midfielder. That has not worked, especially with Ireland's inability to control possession for spells leaving the Burnley player unsure of what to do with himself.
In March's friendly with Turkey, O'Neill experimented with a five-man midfield.
As it happened, the formation didn't matter a huge amount as the basic failings were in ball retention.
Alan Browne and Conor Hourihane, both leading contenders to start tomorrow, spent most of the game shuffling from side to side without joy.
Painfully, it was only the late decision to free Rice into midfield that gave Ireland a bit of control in that area.
He was able to deal with the ball and move it on quickly with a forward pass to bring Ireland up the park. Those skills were particularly evident in the dying stages of the June victory over USA.
Hendrick is Ireland's only available Premier League midfield player and his role in the side should reflect that status.
He should be taking control from the centre with Meyler likely to get the nod in the holding role ahead of newcomer Shaun Williams - although the latter is technically better.
It may well be a choice between Hourihane and Browne for a third midfield spot, much as the option is there to deploy one of that duo as a narrow winger similar to Hendrick's old brief.
Callum O'Dowda was already a likely starter and the McClean blow might just confirm it. It also opens the door for Daryl Horgan, Graham Burke and Alan Judge, three creative talents who are quite versatile.
Horgan would be the form pick after his switch to Hibs, where he has actually shone centrally in a 3-5-2. His old Preston team-mate Callum Robinson, a new recruit, is another candidate.
In normal circumstances, O'Neill would not have considered starting these players for an away qualifier of any consequence.
Tomorrow, he has no other option.