Arsenal duo Per Mertesacker and Yaya Sanogo were involved in a training ground bust-up earlier this season, according to a report.
The Telegraph claims that defender Mertesacker received a black eye following the row with the 21-year-old striker, who was not punished by the Gunners for his action.
However, it was not the same incident that caused the 29-year-old centre-back to play with a black eye during the 5-1 hammering by Liverpool at Anfield in the Premier League on Saturday.
Mertesacker claimed that the second black eye was a result of a stray, but innocent, elbow from goalkeeper Wojciech Szczesny during a practice match this week.