Craig Levein's side need to equal or better the Czech Republic's result against Lithuania when they take on world champions Spain to earn a playoff spot for next year's finals.
"Performance-wise, I know I can improve for Scotland," Adam told Liverpool's official website.
"I'll put my hand up and say that but it's what happens at times. It is difficult to play at international level. But I'm learning and enjoying it and that's the important thing."
Adam has won 14 caps since he made his international debut in 2007.