Celtic believe their players have faced extreme provocation in two of their last four games.
The Parkhead club took on Rangers at the end of March, with their opponents having two players in Alfredo Morelos and Ryan Kent sent off.
At the weekend, Celtic beat an Aberdeen side that were also hit by two red cards after Dom Ball and Lewis Ferguson received their marching orders.
Ferguson was sent off by referee Craig Thomson after a two-footed lunge on Tom Rogic , with the Aussie fortunate not to suffer serious injury.
Neil Lennon is delighted with the restraint shown by his players as he revealed an important lesson taught to him by Martin O’Neill.
Lennon said: "The players showed a huge amount of discipline again in the face of some provocation.
"The second red card was a horrendous tackle on Tom Rogic – it’s two-footed, it’s late, the referee is right there and I don’t know how anyone can argue with that.
"Discipline is really important. Martin O’Neill would stress the importance of keeping 11 players on the pitch and that’s as important today.
"We play the game the right way, as we perceive it, and our discipline, concentration, aggressiveness and purpose were there for all to see on Sunday.
"That was the best performance I’ve had since I have come back in and it really made me smile."
Jozo Simunovic also appreciates the need to remain focused as the club closes in on eight in a row and a historic treble Treble.
He told the Celtic View: "Our opponents never make it easy for us so we must be at our very best in every game and we can only do that if we remain disciplined."
