Ward-Prowse told West Ham's club media: "We can all accept losing a game, that happens in football, but I think the way you lose is important and the most disappointing thing is the way we lost the game.
"I don't feel like we competed anywhere near the level you need to in the Premier League.
"They're a top team who are challenging for the title, but I think they showed us the level and the detail that you need to win games."
The former Southampton captain added: "I can stand here and give a message and try to say something, but I've been a football fan myself and no words could rectify the performance.
"I think it's all about showing, competing, and giving a bit more than what we did. I can stand here and say something, but I know as a fan you want to see something on the pitch."