Ruben Amorim said he will speak to Alejandro Garnacho after the Manchester United forward walked straight down the tunnel following his substitution during their 3-2 win over Ipswich Town.
Garnacho was recalled to the starting XI by Amorim, but was substituted before half-time in response to Patick Dorgu's red card.
The Argentina international was replaced by Noussair Mazraoui and after briefly acknowledging Amorim, he walked straight down the touchline towards the dressing rooms.
Amorim attempted to brush off the incident, but said after the game he would seek out the 20-year-old for talks.
"I'm going to talk, obviously, with Garnacho about that," said Amorim. "So I will talk about that if you want in the next press conference."
Garnacho was dropped by Amorim for the 2-1 win over Manchester City in December along with Marcus Rashford. Garnacho has fought his way back into favour, while Rashord departed after being loaned to Aston Villa during the January transfer window.
Pressed on Garnacho's decision to walk straight down the tunnel after the substitution, Amorim said: "You are making a connection with Rashford, right?
"It was cold and wet, maybe? The thinking was we'd play more in the 5-3-1. I know that is a risk because you are taking one -- maybe the only player who has one against one pace -- but I felt the team was OK in the controlling of the game, almost half-time, then you make the substitution.
"We have to choose someone to go out, we have to think about set pieces also, so it was Garanacho."
