Alan Pardew will investigate after Jake Livermore appeared to become involved in a confrontation with a fan during West Brom's 2-1 defeat at West Ham on Tuesday.
Livermore, promoted to the starting XI after Matt Phillips complained of a tight hamstring during the warm-up at the London Stadium, was substituted in the 64th minute as Pardew sent on Hal Robson-Kanu.
The midfielder seemed to become involved in a disturbance near the West Brom dugout before being led away down the tunnel.
"The only thing I know is I see Jake in the crowd which stirred me," he said. "There is no way he's gone in unless he was provoked severely.
"Of course [we'll investigate it]. I haven't had a chance to speak to Jake. I'll speak to Jake and we'll go from there."
The Baggies led through James McClean's deflected effort but were pegged back by Andy Carroll's firm header shortly before the striker slid in at the back post in the 94th minute to leave the visitors without a Premier League win in 20 matches.
Much was made in the build-up of West Brom's short recovery period having played Arsenal just two days earlier, while the Hammers' last outing was a week ago, and Pardew felt the minimal rest robbed his side of a share of the points.
"The two-day turnaround has cost us in the end and we ran out of legs and could not keep going," he told Sky Sports. "It was heartbreaking for the players. It is such a disappointment to concede a goal like that.
"We were better in the first half, but we conceded too much possession in the second half.
"We were unfortunate to lose Matty Phillips in the warm-up. We had players hanging at the end. I tried to freshen things up, but it was difficult and they had more energy than us and it showed."
David Moyes, who saw his team climb out of the bottom three, had sympathy for his opposite number.
"If I was Alan Pardew I would be completely disappointed with the way it has been set up for them," he said.
"We play again in two days, but at least Tottenham are in the same position."
