Lascelles wasn't involved in this afternoon's 2-1 defeat to Chelsea because of an ankle problem.
However, United's captain is also understood to have had an argument with Benitez ahead of the Premier League fixture.
Asked about reports of a bust-up, Benitez said: “All my life I like to talk with players. We decide with what we have to do. Everyone knows that. If players have different opinions, then we have to speak about it. That’s it, and then we stick to the plan.”
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Benitez was also without Jonjo Shelvey (thigh), while Kenedy was ineligible and Isaac Hayden was suspended.
“We had six players out of the team," said Benitez. "(Javier) Manquillo, Jamaal and Jonjo were injured, Kenedy couldn’t play and Hayden was suspended.
"For a team like us to lose six players, we had problems. Jonjo was tight. Maybe he will need a couple of weeks. Jamaal, hopefully, will be fine for the next game."