Maurizio Sarri believes Mateo Kovačić could play a key role for Chelsea on the left or right of a midfield three.
The Croatia international was brought in on a season-long loan from Real Madrid as part of the recent deal which saw keeper Thibaut Courtois join the Spanish club.
He has played in a number of positions and often featured for Real in an advanced role.
Blues boss Sarri said: “I expect a lot from him because for me he is a very great player and in my opinion he can improve more.
“I think he can play in the three midfielders; centre-right or centre-left is the same for him.
“He is a very good offensive player but he has improved in the defensive phase in the last two years in Madrid.”
Speaking at a press conference on Friday, Sarri suggested that Kovačić will be among the substitutes for Saturday’s game against Arsenal with a view to bringing him on for his debut.
“I think Mateo will be very useful for us. He is a very good player,” Sarri said.
“At this moment he has to work. I think he is not ready now for 90 minutes. But maybe tomorrow for the last 30 or 40 minutes he can be used.”
Cesc Fabregas has picked up an injury in training and will miss the match against his former club.