Costa scythed Vincent Kompany down with his studs in the air during Chelsea’s 2-1 win over Manchester City.
It was put to Webb by BT Sport host Jake Humphrey that Costa could be staring down the barrel of a ban.
But Webb said: “We’ve had a look and he lifts his foot and puts it into Vincent Kompany.
“We’ve heard talk about retrospective action and I don’t think any will be taken.
“Mike Dean’s in a good position and he sees the situation.
“There’s no other action but to put his foot into Kompany to stop him.
“It’s the foul Mike Dean has penalised him for.
“He has seen it, made a judgement and the FA don’t re-referee situations when the referee has seen it.
“Is it violent conduct? It’s a subjective call.
“He puts his foot out and I think it’s worth a yellow card – but it’s just short of violent conduct.”
