An expression used to say you can't deal with something said on short notice; usually followed by a negative clause (e.g., 'I can't').
急に言われても、今日中に終わらせるのは無理です。
You tell me suddenly? It's impossible to finish it by today.
急に言われても予定があるので手伝えません。
Told me at the last minute — I have plans, so I can't help.
急に言われても準備がないから対応できないよ。
If you say it out of the blue, I can't handle it because I'm not prepared.