WEST BROM’S clash with Middlesbrough was suspended for eight minutes as referee Rob Smith was taken away on a stretcher.
The official received medical attention seven minutes into the game after sitting down on the pitch.
Staff from both clubs tended to him, before he left via the nearest tunnel which leads not to the dressing rooms but outside the ground where the ambulances are usually on standby.
SunSport understands an ambulance was waiting for Smith to take him away.
The fourth official, believed to be Premier League referee Eddie Smart, took over as his replacement.
A man from the stands came down to assume the role of fourth official.
After the match resumed, a statement from West Brom read: “The game is back underway.
“Our best wishes are with assistant referee Rob Smith, who cannot continue after receiving medical treatment.”
Middlesbrough also released a statement sending their best wishes to Smith – who went off when the game was goalless.
It comes as West Brom prepared to pay tribute to supporter Mark Townsend who lost his life after a medical emergency at Sheffield Wednesday on Saturday.
There will be a minute’s applause in memory of the 57-year-old Albion season ticket holder.
West Brom came into the clash at the top of the Championship table with five wins, one draw and one defeat from their opening seven games.
Boro sat mid-table with 11 points from eight matches under Michael Carrick.