West Ham striker Michail Antonio was surprised by David de Gea's blunder on Sunday.
The Manchester United goalkeeper was beaten by a tame drive from Lucas Paqueta as West Ham won 1-0 at London stadium.
Antonio told The Footballer's Football Podcast: “I can't slate the man. I don't really want to slate the man. But De Gea has got to do better. I don't understand, he is such a good 'keeper. But he has these moments, I feel so bad for the guy.
"He was up there as one of the best 'keepers in the world, even though he is up there, he still has these crazy moments.
"That goal, it was so slow. When I saw the shot I thought, 'he is just going to collect this'."