Y has been in a heated discussion with another person. X has been observing that discussion / argument:
Yの目が、なんとか怒りを抑えつけようとしているのを、Xは見てとった。
"X could see the suppressed anger in Y's eyes."
How does Japanese sentence structure allow for a comma between "目が" and "なんとか"?
btw: When speaking, I don't think you'd do a pause there.