Manager Mauricio Pochettino confirmed to reporters this afternoon that the England winger was omitted as a direct result of his altercation with the club's fitness coach Nathan Gardiner following the conclusion of Monday's 3-1 win over Aston Villa.
"Because of Monday, he is not available for selection. When you behave in the wrong way, you always need to pay. Discipline is very important to me," said the Tottenham boss.
"We have a young squad who can make mistakes but when you cross the limit it's important to stop that. Sometimes when you don't play as much as you expect, I can understand it, but it's not the way to impress the manager.
"He needs to learn about football, which isn't just playing the game. He needs to learn about behaviour, discipline. You need to have the responsibility of a professional."
In recent weeks 24-year-old Townsend has been linked with a move to Swansea City.