The defeat saw the Whites slump to their sixth defeat since they were promoted back to the top flight of English football.
On set-piece troubles again for the Whites
Another poor display from United when trying to defend or attack set-pieces and the Argentine was asked what he was doing to solve the problem.
"There are no mysteries to the things we have to do. The set-pieces can be perfected by continuously training them in the training," he said.
"You have to reproduce what happens in the game in the training session, we will continue insisting on this until we can resolve the problem.
What’s happening is not excusing me with that being done. This problem we’re having, we’ve already had it before in the past, we resolved it and now it’s happening again." Bielsa continued.
Encouraged by how close the games have been
Bielsa, who took charge of his 113th game in charge of the Whites, was asked if he felt encouraged by how close the games have been recently and he didn't think that was the case saying: "That’s not the case. We’ve lost 4-1 twice, 3-1 and today the result should have been by a bigger scoreline.
We could also have drawn the game, but the game could have been lost by a bigger margin."
On West Ham dominating the game
United boss Marcelo Bielsa was asked what happened in the end to see the visitors dominate the game and he was fair with his assessment on the situation: "The most important aspect is linked to how we recover the ball after our attacks finish.
When the attacks don’t finish in the opponent’s box, and it’s not easy to finish attacks in the opponent’s box, it’s difficult for us to recover the ball, this generates consequences in our game and we struggle as a result."
On choosing Roberts instead of Hernandez
In the second half when Leeds were looking for something back in the game Bielsa opted to bring on Tyler Roberts instead of the Spanish playmaker Pablo Hernandez and after the game Bielsa explained his reasoning: "Because I substituted the striker and the characteristics of Tyler Roberts are that of a centre forward and the characteristics of Pablo Hernandez are that of an offensive midfielder.
Unless the question is why didn’t I put Pablo Hernandez as a striker?" Bielsa said.
Players a little naive in way they play
Some pundits and fans have been thinking the players are a little bit naive in the way they are playing recently especially in the past two games against Chelsea and West Ham, however, Bielsa said: "No, I don't [think they a little naive]" when asked by the media after the game.