The talented teenager arrived at the Latics this summer with a glowing reputation, having made a name for himself in the SPL with Hamilton.
The 18-year-old is regarded as a hot prospect for the future, with a number of clubs believed to have been chasing his signature prior to his switch to the DW Stadium.
McCarthy accepts that he still has much to learn, and must bide his time before becoming a Premier League regular, but he has revealed that he is desperate to prove his worth to the Wigan supporters after seeing his progress in England hampered by injury.
"I am still young, I need to bide my time and hopefully when I get my chance I'll be able to take it," he told the Wigan Evening Post.
"You are always learning. Coming down here has been a big learning curve for me, but I'm enjoying it.
"I've got the gaffer (Roberto Martinez) and Graeme Jones looking after me as well as the other boys, and I'm happy with how it's gone so far. I just need to keep plugging away.
Test"There are lot of big-name players here and it's just a case of fighting my way into the squad and then the team.
"It has been very frustrating for me, but we have got a lot of top players at this club.
"No disrespect to the Scottish game but there are a lot more top-quality players in the Premier League in England, and I want to try to test myself against them."
McCarthy has been building up his match fitness with Wigan's reserves of late, while he is also hoping to be awarded a run out for Republic of Ireland's U21 side in their upcoming European Championship qualifiers against Georgia Switzerland.
"Match fitness is what I need now, and that's what I've been getting in the reserves," he added.
"It's a decent standard, and I'm happy to be playing 90 minutes trying to get my fitness levels up.
"I'm feeling fine at the moment, and I'm hoping to get another couple of games under my belt for the Republic of Ireland as well."