Jose Mourinho has said Manchester United could switch their focus from the Premier League to the Europa League if they lose sight of a top-four finish this week.
United are currently fifth, five points behind fourth-placed Manchester City with a game in hand, after having to settle for draws against Bournemouth and West Brom in their last three league games.
They face Everton on Tuesday followed by rock-bottom Sunderland on Sunday, and among the eight games that follow they must face Chelsea, City, Arsenal and Tottenham.
Mourinho had previously indicated he may prioritise the Europa League -- where United are favourites and face Belgian side Anderlecht in the quarterfinals this month -- as that competition may provide an easier route to Champions League qualification. While he has not yet given up on a top-four Premier League finish, he said that could change after their next two games.
"I just want to think that against Everton we are going to do what we tried to do [against West Brom], to try to play with our best team and try to win the match, and after Everton we go to Sunderland with the same perspective," Mourinho told reporters. "And then after Sunderland the Europa League comes and I don't know.
"Then, it's possible that you see me play in the Premier League with a team where I'm going to protect the players that I consider fundamental for the Europa League -- but only, only if the results in the next matches put us in a situation where, mathematically, it becomes almost impossible to do it.
"I go with mathematics. Until it's impossible mathematically, we keep trying. Because this week is a week without the Europa League, we have nothing to think about with the Europa League. This week is easy. From the focus point of view, it's easy. We have to play Everton, we have to play Sunderland, and in these two matches we have to go for them thinking about the Premier League and nothing else.
"After that match against Sunderland, then we have Anderlecht and the quarterfinals of the Europa League are very important for us."
Mourinho praised his defence but was critical of his attack after the 0-0 draw with West Brom, saying the players selected -- Marcus Rashford, Jesse Lingard, Anthony Martial and Henrikh Mkhitartyan -- lacked consistency and had missed "incredible chances."
"It's every day [they miss], so I keep doing what I'm doing during the season," he added. "I give chances. I try. Play again. Come on. Keep going. You have talent. They know they have talent. OK, let's go. Let's try. Let's have one more opportunity. No pressure. Keep going. There is nothing else we can do."
Zlatan Ibrahimovic will be available for the game against Everton after serving a three-match suspension for an elbow in the 1-1 draw with Bournemouth, but Mourinho said: "We've had matches here with Zlatan that we drew.
"He [missed] a penalty in a game to win it 2-1 [against Bournemouth]. He missed chances like other people did too, so I cannot say now that if Zlatan and [the injured Juan] Mata played, we win against West Brom. I cannot say that.
"What I can say is that [Phil] Jones and [Chris] Smalling, they would not play better than [Eric] Bailly and [Marcos] Rojo did. [Paul] Pogba and [Ander] Herrera could not play better than [Marouane] Fellaini and [Michael] Carrick did. That I can say for sure."