The Germany star has attended an event in Miami against racial abuse in the sport to support his brother Kevin-Prince
The Rossoneri midfielder walked off the pitch after abusive shouts from the stands during a friendly against Pro Patria in January.
And speaking at an event against racism in football in Miami, the Bayern Munich man has called for action against abusive behaviour from supporters towards players.
"I'm happy that I could make it but I think we must do more," the 24-year-old centre-back told SWOL.
"Like this is the start of the event and we must do more.
"I'm proud to be a part of it and I'm happy to be here in Miami at this time. I'm looking forward to this event and I think its an important thing.
"It was also a reason [I support this event], because it's my brother and because thats why I tried my best to come here.
"We need people in a really big positions to show that it is very important and that it doesn't happen again in the stadium, because we all love this game and its about respect."