Bruno Fernandes expressed his dismay at being substituted in Manchester United's goalless draw with Liverpool when Scott McTominay had just been injured.
The United staff were about to remove Fernandes for Mason Greenwood but McTominay went down and required treatment from the club physio Richard Hawkins.
United manager Ole Gunnar Solskjaer instructed goalkeeping coach Richard Hartis not to put the electronic board up after the Scot urged United to wait on making their substitution.
Fernandes was confronted by Liverpool midfielder Georginio Wijnaldum, who urged the Portuguese to leave the pitch even though United had not confirmed the change.
McTominay soon signalled he was fit to continue and United pressed ahead in withdrawing Fernandes, who audibly complained as he marched off.
"It was a tactical decision," Solskjaer said. "Bruno has been running his socks off every single game since he came. He has been here a year and running more or less every game.
"Towards the end, we felt Paul’s physical presence in there might be a chance for us and Mason, when he gets a chance, can score in the blink of a second. So it was a bit of a throw of the dice to put Mason on even though he had to defend against Robertson."
Luke Shaw was arguably United's standout performer at Anfield and has successfully fought off competition from fellow left-back Alex Telles since the Brazilian arrived from Porto on deadline day in October.
Shaw, 25, has not been outright dropped in favour of Telles and swiftly regained his place after a hamstring injury that left him sidelined for over a month.
"Luke has improved immensely," Solskjaer acknowledged. "I thought today he showed his strength, quality and composure on the ball, delighted with his performance."
