WATCH: Ander Herrera appears to spit on Man City badge as he leaves Etihad pitch

Professional footballers spit a lot. It's just what they do.

Thankfully, although there have been one or two exceptions down the years, it's usually just on the ground and not at people. This said, it seems Manchester United's Ander Herrera has still managed to cause some offence by seemingly doing exactly that during Saturday's Manchester Derby. Footage doing the rounds on social media on Sunday appears to show the Spaniard spitting on the ground as he makes his way to the changing rooms at half-time. His spit appears to be directed at the Manchester City crest seen on the floor just outside the Etihad Stadium's players' tunnel - hence the reason some City supporters aren't too happy about it. Clearly, nobody really knows if it was intentional or not - although enough United fans appear to think it very much was. https://twitter.com/ManUtdChannel/status/982998977581846528 https://twitter.com/markgoldbridge/status/983006050570899456 https://twitter.com/UtdViews/status/982999269291339777 At the time of the incident, United trailed City 2-0. Goals from Vincent Kompany and Ilkay Gündogan had put Pep Guardiola's side in a commanding position to clinch the title against their great rivals. However, having failed to add to their two goals, City were pegged back in the second half. A much more positive performance from the visitors saw Paul Pogba score twice to pull United level. Then, with little over 20 minutes remaining, Chris Smalling added what proved to be the game's decisive goal to complete a famous comeback for Jose Mourinho's side.