He didn't need to do it but Manuel Pellegrini brought Fabian Delph on for Manchester City during the second half of their 0-0 draw with Aston Villa.
It was a frustrating afternoon for City but a point was still good enough to keep them top of the Premier League before the north London derby.
When Delph came on, though, the whole of Villa Park - many of whom held their inflatable snakes aloft - booed loudly.
Aston Villa fans feel Manchester City supporters will never understand why they are angry with Delph for leaving them. It's not the fact he left itself but the manner in which he betrayed the Midlands outfit.
City fans, however, have jumped to the 25-year-old's defence on Twitter and vigorously defended him on social media after the 0-0 draw.
Many Manchester City supporters also hit back at the Villa faithful, tweeting that their behaviour on Sunday was... far from exemplary. It seems the Delph debate will forever rage on and there will at least be peace until the two clubs next meet.
Here's how Manchester City fans reacted to Aston Villa fans' treatment of Delph on Twitter:
#Mcfc Disrespectful villa fans today we never treat our ex players as badly as they did in Fabian Delph so disappointed he didn't score— Caroline Holmes (@Caz11holmes) November 8, 2015