The American winger was linked with moves away from the club during the summer.
A loan to Manchester United was even suggested, but no transfer materialised.
Henry stated on CBS Sports: "I think by now we would have known if he could play.
"He has been at Chelsea for a very long time. I thought Christian Pulisic was going to leave. I think it was time for him to leave. But he didn't.
"It's over. That's going to be the case up until the World Cup. He has to find a way to play. Raheem Sterling is in front of him.
"They also have Pierre-Emerick Aubameyang. But I thought [Pulisic] was going to leave."