Arsenal manager Arsene Wenger has criticised Andre Santos for taking Robin van Persie’s shirt at half-time on Saturday.
Van Persie, who left the Emirates for United during the close season, scored the opening goal of United’s win over his former club at Old Trafford.
As the side’s left the pitch at half-time, Santos embraced the Dutchman and took his shirt from him.
Wenger has admitted that he feels the Brazilian’s actions were wrong, but said his side have more important problems to focus on.
“I spoke about that but I don’t want to make too much of a big story of that,” Wenger said of Santos’ exchange with Van Persie.
“I believe that was not the right thing to do at all, but that is not an explanation for our bad performance on Saturday.”
The Gunners have made a stuttering start to the season and sit sixth in the Premier League, nine points off league-leaders Manchester United.
Wenger’s men face a midweek trip to Germany to take on Schalke in the Champions League before a Premier League clash at home with Fulham on Saturday.