Koeman received his marching orders after he protested a yellow card given to Sergio Busquets.
The former Everton trainer had been expostulating with the referee for most of his decisions in the game.
Despite being sent off during the game, the under pressure Barcelona gaffer in a post match presser advocated he did nothing wrong to deserve the harsh treatment from the referee, insisting he was sent off for removing an extra ball from the pitch.
"In this country they send you off for nothing," Koeman remarked.
"Everybody saw that there was a second ball on the pitch except the referee. "In general, the team played well. We had a lot of possession," he added.
"It was difficult to create many chances but we did have the best ones in the game right down to the last minute.
"And with Memphis in the last minute, even with one less player, I would never complain about the attitude of the players today.
"It’s very difficult. You have to have a lot of creativity here and in this game maybe we were missing the last pass. It was a game where we thought we would score but if you don’t score, you don’t win games."
The Catalan club have failed to win their last two LaLiga games and are currently with 9 points on seventh position after five games.
