Chelsea goalkeeper Thibaut Courtois has hit out at West Bromwich Albion by claiming that the team set out to "provoke" Guus Hiddink's side on Wednesday night.
The Baggies came from behind twice to seal a 2-2 draw at Stamford Bridge.
"I think [Yacob] should have been sent off," Courtois told Chelsea's official website. "Their manager took the player off one second after the foul so I think everybody knows that was clear.
"We're very disappointed. It was a game we wanted to win. It was a tough game with them playing only long balls, [playing for] second balls, trying to provoke players.
"It was a bit frustrating. We tried to do our best, we came back, but sadly they got the second goal."
The Blues are currently 14th in the Premier League table.