The pair clashed at the end of Arsenal's 5-1 humiliation at Tottenham and had to be separated by teammates.
A source told The Sun: "The first thing Adebayor said to Bendtner was 'I'm only on because you are so s**t!'
"He has been on Bendtner's case for a long time.
"The pair do not get on and it finally boiled over on Tuesday night when Adebayor came on as a sub with the team 4-0 down.
"Bendtner ignored him - but when Adebayor said the same thing again later on, Nicklas gave Manny the finger and it all kicked off."
The warring team-mates had to be pulled apart as Adebayor nutted Bendtner in the face.