Manchester City players clashed at the end of their 1-1 draw with Champions League opponents Borussia Dortmund.
The Daily Mail says City strikers Sergio Aguero and Mario Balotelli are said to have had a heated argument after the 1-1 draw over who takes the penalties.
Substitute Balotelli converted the late spot-kick, but the taker of the next penalty is yet to be resolved. Balotelli, with his great record from 12 yards, is the most likely choice.