Former Manchester United manager Moyes is determined to make a strong start to life at the Hammers.
"Am I approaching this in a more aggressive manner than recent jobs? Yes," Moyes said at his pre-match press conference. "I've just not got any time for any nonsense.
"Because as you know, I'm short here at the moment. I've not got any time, I'm not going to be pampering to any needs. I can't be bothered.
"If anybody says that they can't get back from international duty, well don't think you will be coming in and playing Saturday. It's that sort of thing. It can't happen any longer."
Victory for West Ham over the Hornets would lift them out of the relegation zone.