West Ham boss David Moyes says they will introduce Lucas Paqueta gradually.
The midfielder arrived from Lyon this week.
Moyes said, "Settling in is always going to be difficult for any player. Overall, Lucas Paqueta is in and trained yesterday.
“We want to get him involved but we want to be fair and give him a chance to get to know the players and how we play, and getting used to the Premier League as well.
"Ben Johnson is not available and we're still waiting to see how Gianluca Scamacca is and how Aaron Cresswell is. It'll be a late decision for both of them."
The Scot also said: "I've think we've tried to bring in players we really believe can keep us up near the top end. I think the top clubs have recruited well also. We're trying to keep up with them, that's the job.
“Hopefully, in time, we can get the players to show how good they are. We needed the players in. We were short and I think it was always going to be a year where we needed eight new players."