After a respectable 2-0 defeat to the USA in Austin on Saturday night, the Republic of Ireland flew straight to Missouri for the rematch, which kicks off in the very early hours of Wednesday morning [12:30am Irish time, live on RTÉ2].
The Americans' victory was tarnished by free-scoring attacker Mallory Swanson suffering a torn patella tendon in her left knee following an unfortunate first-half tangle with Aoife Mannion.
Swanson was stretchered off and taken to hospital, with her World Cup dreams hanging by a thread. Head coach Vlatko Andonovski looked a worried man as he walked on to the field to inspect the extent of her injury; but he's not exactly short of options.
Trinity Rodman replaced Swanson and showed evidence of why she's the highest paid player in the NWSL, while Swanson's withdrawal from the squad has opened the door for rising star Alyssa Thompson to come in. The 18-year-old has burst onto the scene at Angel City this year.
The USA were also significantly lifted by the 67th-minute introduction of powerful midfielder Julie Ertz, back for the first time since giving birth to a son last August. However, Rose Lavelle, arguably the best player on the pitch, will not be involved tonight after picking up a slight knock, while Andonovski has strongly hinted he'll use this second friendly to get a closer look at his squad players.
The USA were comfortable winners on Saturday but Ireland put it up to their illustrious hosts in a well-executed first half in which they looked solid in defence and dangerous on the counter.
Pauw handed Sinead Farrelly her debut just 24 hours after the US-born midfielder's international clearance had been confirmed by the FAI.
Farrelly is only returning to the game this season after an eight-year absence but she validated Pauw's pre-game assertion that she "can make the ball free" with a very composed performance. The 33-year-old was withdrawn after an hour and admitted afterwards she's still got work to do, mentally and physically, as she readjusts to elite football, but - barring injury - you can bank on her being on the plane to Australia.
It's obvious Pauw has a clear vision of how she wants the team to set up, and within that vision she requires a midfielder with the ability to retain possession in tight spaces. Farrelly is that player.
Her arrival means the scramble for midfield places has suddenly become even more intense.
Farrelly will start on the bench tonight, as will Mannion, with Pauw conscious of managing their work loads. But the manager has a full, fit squad to choose from.
Ruesha Littlejohn came on for the last half an hour on Saturday and should get a run from the start, while the likes of Lucy Quinn, Jamie Finn and Ciara Grant will be desperately hoping for a chance to impress. Megan Connolly may drop back in to the centre of defence to fill in for Mannion, thus opening up another midfield berth.
Heather Payne operated at right-back at the weekend with Pauw opting to use Kyra Carusa as her lone striker. That experiment worked well on both counts - Payne excelling out wide while the intelligent Carusa offered a different dimension up top.
Katie McCabe played left wing-back in the absence of Megan Campbell and may be nudged further up the field this time. If that's the case, Aine O'Gorman, Harriet Scott, Claire O'Riordan and Jessie Stapleton will be among those hopeful of slotting in to the defence.
The long-held strategy of playing the strongest possible opponents in friendlies has served Ireland well. They were able to take a lot of pluses from Saturday's defeat, even if they admittedly faded after the hour mark and never looked likely to get back into the game on the turnaround.
The Girls in Green have shown an ability to learn quickly from defeats so this rematch will be instructive.
"We're looking forward to this second game against USA as there were a lot of positives for us to take out of the first game in Austin," said Pauw.
"We'll make some changes with both Aoife Mannion and Sinead Farrelly not starting this game due to injury prevention as we need to protect them because of their limited game-time at club level.
"This game is another opportunity for us to test ourselves under the pressure of playing against a quality team. It is a challenge that we will embrace as it will help our preparation for the World Cup."
Pauw was frustrated by the defensive lapses that cost Ireland two goals four days ago, as was Louise Quinn, who had a header cleared off the line by Alex Morgan when the game was scoreless.
However Quinn also talked up the feeling of progress within the camp.
"We're putting it to teams, creating chances," the centre-back said. "We feel those goals are preventable. We're coming off the pitch a little disappointed, because we had chances."
Creating them, and taking them, will be key once more in tonight's clash which takes place at CityPark, a brand new 20,000-capacity stadium constructed to host MLS side St Louis City.
Ireland will use the occasion to debut their new Castore away kit. It'll be their last match until 22 June, when they host Zambia at Tallaght Stadium.
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