West Brom head coach Steve Clarke slammed defender Goran Popov following his sending-off for spitting against Tottenham, admitting he was"absolutely disgusted" with his behaviour.
Popov faces a three-match ban as a result of the incident, which came early in the second half after he had exchanged angry words with Spurs defender Kyle Walker.
Clarke confirmed disciplinary action will be taken against the Macedonia international, adding that his dismissal played a large part in Albion's 1-0 defeat at The Hawthorns.
A second-half goal from Gareth Bale earned victory for Spurs, who are now only a point behind third-placed Chelsea in the Barclays Premier League.
Clarke said: "The game changed with the sending-off. I'm absolutely disgusted with Goran's behaviour.
"One of the group has let the players down. It changed the whole complexion of the game.
"It's difficult enough in the Premier League playing against 11 players, especially when you're playing against Tottenham.
"There's no excuse for that. There's no place for it in life, never mind on a football pitch.
"I would like to think that at some stage he will apologise. As always there will be disciplinary procedures taken against the player but they'll remain in-house."
Tottenham manager Andre Villas-Boas echoed Clarke's sentiments.
He said: "It's difficult for the ref, but Popov did what he did and Walker did nothing to react.
"It's difficult to assess but I think Mark Clattenburg made the right decision.
"It's horrible and nasty."
Albion defender Jonas Olsson also appeared to gesture towards Baggies fans after he had been jeered after making a mis-placed pass, but Clarke said: "I didn't see that one. I'd have to see that again."
Bale's superb strike brought the Wales international his 11th league goal of the campaign.
Villas-Boas admitted he would consider using Bale as an out-and-out striker after Jermain Defoe suffered a first-half ankle injury that is likely to sideline him for a number of weeks - in addition to forcing his withdrawal from the England squad to face Brazil at Wembley on Wednesday.
"We started today with Bale through the middle and Clint Dempsey on the left," said Villas-Boas. "It is something he feels comfortable with.
"It gives us even that possibility for sure. It is something we have to look to."
On Defoe's injury, Villas-Boas said: "He will have a scan and only when we see the results will we know the extent.
"It is a big blow because he is an important player and person for us, on and off the pitch."
Tottenham have collected four points from two away games at Norwich and Albion in the space of four days, and Villas-Boas admitted: "It has been a very important week for us.
"To get four points away from home, with not much time between the games, is excellent.
"We have put ourselves in a very good position to threaten for third place.
"I am extremely happy apart from the big setback to Jermain Defoe."