Martin Keown slammed Kyle Walker for 'losing his head' after the Manchester City was sent off for a petulant challenge as the Premier League champions lost 2-1 to RB Leipzig.
The England international received his marching orders three minutes from time, as he needlessly took a swipe at the Portuguese's left leg.
While City topped the Group A despite losing in Germany, Walker's sending off means the right-back will miss the first leg of the Round of 16 in February.
Keown, who was commentating on the game for BT Sport, was far from impressed with the incident.