For so much of the season, Cardiff City had a major problem at right-back.
Leandro Bacuna had to fill in as a makeshift option there following Jordi Osei-Tutu's injury, however Perry Ng has come in and made everything right again on that side of defence.
In contrast, at the same time the Bluebirds were struggling on the right, they had an overload at left-back; Joe Bennett, Joel Bagan and Greg Cunningham all vying for one spot.
Cunningham has moved to Preston, Bennett has sustained a horrible ACL injury and Bagan dislocated his shoulder in the 0-0 draw with Huddersfield Town last Friday.
It prompted McCarthy to hand Ciaron Brown his league debut up at The John Smith's Stadium, a proud moment for him and he did well, earning his first Championship clean sheet in the process. He was solid over on that left flank.
However, with the return of Jordi Osei-Tutu, albeit he is a couple of weeks from full fitness, and with Tom Sang having played well over on the other side on Friday night, some have questioned whether they could be roped in to play on the other flank to add that attacking edge.
While Brown filled in well on that wing, he is a centre-back by trade and there is a school of thought that City might lose some attacking impetus playing a more naturally central defender out on the touchline.
But McCarthy is keen to place his trust in youth. His philosophy is clear: if they do not get a chance then we will never know.
When he first arrived at Cardiff, one of his most trusted scouts told him he had a real player in Brown, who at the time was on loan with Livingston up in Scotland, and that he should bring him back to Cardiff.
McCarthy did just that and now, not wanting to repeat mistakes from the past, it appears the manager will afford the Northern Ireland international a stretch in the team.
"I think he did well," the manager said of Brown's performance against the Terriers. "I don't think he did, he did well on Friday night.
"There is no reason to go and explore any other options.
"The other option is playing a right full-back at left-back and I've made that mistake in the past. I did it when I was a very young manager at Millwall.
"I could have played a young one there and I ended up playing a centre-back at right-back and the centre-back had a bit of a 'mare and the other right-back never got a chance.
"So, unless you play them you will never truly find out anything about them.
"He has earned that position."
The 23-year-old has earned his shot and he now has 11 vitally important fixtures ahead of him. The Bluebirds are fighting tooth and nail to get into those play-off spots come the end of the season and he will be desperate to play his part in that.
On a personal note, Brown's contract with the club is up this summer, but Cardiff have an option to extend it if they feel it is right to do so.
Having had no league exposure with the Bluebirds until Friday night, he now has a massive chance to prove his worth.