The Northern Ireland international was hit under his left eye by a coin thrown from the visiting section as he went to hand his shirt over to a Baggies supporter following their 3-1 FA Cup defeat at Reading on Saturday.
The police are treating the incident as assault with the FA also investigating while Albion will issue a lifetime ban to anyone found guilty.
Brunt was then involved in a heated exchange with a group of fans and believes the coin may have blinded him.
“It could have done but it is done now, you can accept criticism and accept people having a go at you in games for not playing well individually or as a team but you can’t accept people throwing stuff,” he said.
“I can’t pick that coin up and throw it back at him. If I did that, I’d be all over the news and sitting in a police cell. It is definitely not on.
“I was pretty angry in the heat of the moment. I don’t know who threw it , I don’t know where it came from. It is a brave man to throw a coin from there and a braver man if he admits to it.
“I don’t really see how that was any different to whacking someone in the street. We are not allowed to do it and nobody is allowed to do it in the street so why should he be allowed to throw coins at football matches?
“He was probably lucky the police were there otherwise he might have got collared by me if I had known who he was.”
But Brunt does not expect anyone who threw the coin to apologise to him despite widespread condemnation about the incident.
He said: “Probably not, but it would show and make him a bigger man than what he was to throw a coin from 20 yards away to hit me in the head if he owned up to it. You are throwing football back 20 years with some of the behaviour there.”
The 31-year-old is Albion’s longest-serving current player having made 313 appearances since joining from Sheffield Wednesday in 2007.
He added: “Nobody deserves that, it doesn’t matter whether I have been here 10 years or 10 minutes.”
After a goalless first half, Darren Fletcher looked to have put the Baggies on course for the quarter-finals when he broke the deadlock in the 53th minute.
But Ireland’s Paul McShane grabbed a quick reply as he headed home from an Oliver Norwood free-kick and Michael Hector repeated that feat to put the Royals ahead 18 minutes from time.
Saido Berahino and Fletcher had late chances for West Brom but Chelsea loanee Lucas Piazon settled it in injury time.
Buoyed by the shock win, Oliver Norwood has called on Reading to use their FA Cup experience to reach the final.
Reading were beaten semi-finalists last season, losing 2-1 in extra time to Arsenal, and Norwood wants it to help them this term. “We enjoyed the run last year and the experience of getting to Wembley and playing Arsenal in the semis,” said the 24-year-old. “Hopefully we can replicate it this year — and maybe go a step further.”
Habsi, Gunter, McShane, Cooper, Obita, Robson-Kanu, Norwood, Hector, Quinn (Piazon 90), Rakels (John 59), Cox (Vydra 59).
Bond, McCleary, Ferdinand, Barrett.
Foster, Chester, Evans, Olsson, Brunt, Sessegnon, Fletcher, Sandro (Pritchard 82), McClean (Anichebe 75), Berahino, Rondon.
Yacob, Gardner, Myhill, Pocognoli, Lambert.
Anthony Taylor (Cheshire).