Martin O'Neill has described Ireland winger James McClean's sending off for a reckless tackle on Bournemouth's Adam Smith on Saturday as a moment of "red mist".
McClean was dismissed by referee Mike Dean during West Brom's 2-1 home loss to the Cherries.
"I like James, I like James a lot," he said.
"I gave him his debut at Sunderland I believe. And he certainly turned our fortunes around. And this (tackle on Smith) is red mist.
O'Neill recalled McClean's impact on Ireland matches can often swing games in their favour.
"His impact in the Republic of Ireland side has been terrific, absolutely massive - some games he has really turned for us," he said.
"But even Roy said to him (before he went on the field on this occasion), 'just be careful now, don't do anything reckless'. Thirty-five seconds later he takes someone's leg off."
Smith, meanwhile, has hit out at McClean after claiming the West Brom man could have broken his leg.
The pair had clashed just 10 seconds earlier with McClean angry he did not get a first-half free-kick following a 50-50 challenge between them, and Smith said: "He could have broken my leg."
Smith, who scored Bournemouth's first goal, told reporters after the game: "Personally I thought it was a very dangerous challenge.
"I could see out of the corner of my eye that he was sprinting towards me so I knocked the ball and as I knocked the ball I jumped because I knew he was going to come for me.
"It was lucky I did because if my leg was standing I could have been hurt. I don't know but he could have done a lot of damage. "It was right in my shin and it was hard as well but luckily I jumped out of the way.
"I don't really know what happened before. Maybe he thought I fouled him, I don't really know. It was a 50-50 and maybe I caught him, I don't know."
Charlie Daniels netted a late penalty to win it after Gareth McAuley levelled, with the Cherries recording a third straight victory after also beating Chelsea and Manchester United.
Smith said: "Teams are going to be a bit more wary of us now because we've shown what we can do.
"But that doesn't affect us. We're going to keep playing the way we are and get as many wins as possible."
Salomon Rondon was also dismissed for the Baggies for pushing his head into Dan Gosling in injury time.
Both he and McClean will be banned for three games with West Brom boss Tony Pulis confirming they will be disciplined.
He added: "They will both get fined.
"With the first one he should really book Smith, it's a free-kick for us, it's that poor a challenge (but) McClean shouldn't react like that."