"It is always difficult when playing a team facing relegation," said Benitez.
"They put more passion in, maybe. It's a massive difference to go to the Championship after playing in the Premier League.
"It will be a tough game for us. They are fighting.
"Why can't they stay up? The thing is, we have to win - that makes it more difficult for them. But anything can happen in football - the difference is not too big."