McGrath is the key man as Waterford seek to get heads right for battle of the south-east
More than any other round in this era of the back door, the hurling quarter-finals are as much about what's in your head as in your wrists.
Just take the Waterford hurlers, being touted as genuine contenders just a fortnight ago, as the upbeat prelude to the disastrous malfunction of Derek McGrath's seemingly well honed system.
But it also applies to a Wexford team suddenly emboldened by recent exploits.
Back in May, bedevilled by injuries and doubt after a pretty miserable league, they started with some fire against Dublin but it extinguished inside 20 minutes ... cue an apologetic Leinster exit.
"Sometimes we just have those kind of days," admitted Lee Chin, who sat out that game through injury.
He was back for the qualifiers and his influence against Cork was profound. But there was more to this renaissance than one player.
"We believed we were going to come up here and put in a performance," Chin told The Herald afterwards. "We've been in this position before when we came up here not really believing in ourselves, but in the last six weeks we've really turned it around."
Enough to floor the Déise?
What happened in the Munster final was a shock not so much because people questioned Tipperary's capacity for plunder, but rather because very few foresaw the disintegration of Waterford's defensive wall in the face of Tipp's aerial onslaught.
What followed was the concession of five goals and a 21-point humiliation.
And this brings us back to our 'intro' about Waterford's head space and their potential mental fragility.
For all the schadenfreude from the hurling traditionalists, who delighted in the implosion of their defensive set-up, the last thing Waterford should do now is tear up the script in some wild panic.
Modify and tweak? Yes. But this system has yielded 18 months of pretty stellar consistency. And while the very top teams (Tipp twice, and Kilkenny last August) may have figured out how to beat it, most others have struggled to cope with Waterford playing this system at optimum intensity - and accuracy.
Wexford have forwards who can punish any repeat of their recent defensive disarray - not just Chin and Conor McDonald, but also Liam Óg McGovern and the ball of energy that is David Dunne.
More than any one player, McGrath will have been the key man for Waterford in the build-up to this battle of the south-east. On the proviso that shaken self-belief has survived their trial by Tipp, there should be a backlash coming and it should propel them into the last-four.
ODDS: Waterford 1/6 Draw 14/1 Wexford 9/2 VERDICT: Waterford
All-Ireland SHC q-final: Waterford v Wexford, Thurles, tom (2.0), live RTé 1