Newcastle United boss Eddie Howe felt Kai Havertz should've seen red during victory over Arsenal.
Newcastle won 1-0 via a controversial Anthony Gordon winner.
But before then Havertz escaped a direct red for a high challenge and Howe said, "We were close to the incident, I thought it was high and potentially dangerous.
"He was lucky to get a yellow. There was a lot of yellow cards and I don't think there needed to be - it wasn't a dirty game but there were a few flash points.
"Keep 11 players on the pitch was the message at half time but not lose fighting spirit and desire. We kept our heads really well in the game."