Rafa Benitez reacts to Mohamed Diame's powerful performance for Newcastle
Diame – who had gone to the tournament with Senegal – started Saturday's 1-0 win over Derby County.
The 29-year-old, signed from Hull City last summer, put in a powerful first-half performance at St James's Park against Steve McClaren's side.
However, an injury to Isaac Hayden after the break saw Diame given a more defensive role.
"He was making a difference," said United manager Benitez. "He was doing really well.
"After (Hayden went off), we lost a bit of this control, because in these areas he was a threat.
"We needed to manage. It was a decision we had to make during the game. We had to do it."
Benitez and his staff are assessing Hayden ahead of Saturday's Championship games against Wolverhampton Wanderers.
Newcastle lead the table after the weekend's results.