"It's been frustrating, I've not played nearly as much as I want but that is part of life in football," he said.
"I've spoken to the manager to see where I'm at and I'm still in his plans which is a positive thing, but at the end of the day I'm not playing so it's been frustrating."
A lack of regular action meant O'Dea was determined to seize his opportunity to catch the eye in the clash against England Under-21s on Tuesday evening at St Mary's.
"Games like the England match are massive for me, in terms of playing and the fact that there are a lot of people watching," he added.
"Without playing club football I can't even dream about the seniors, it's a matter of getting my club football right before moving up to that."