Nigga go learn it yourself. If you a malnourished dark skin then you’ll get the somalia nickname.In the Donbas region where Russia and Ukraine are fighting, there is a battalion named "Somalia". They were given that nickname because of their bravery in fighting successfully against Ukrainians since 2014.
In Yemen, when people want to swear but don't want to say wallahi, they swear to "kalimatul Somal", meaning I swear to the Somali word. Apparently, Yemenis saw how the Somalis swear with the "Wallahi" a lot while in the Arab world, it is extremely rare cases that they use it.
That Brazilian player was probably named Somalia because he is an Afro Brazilian who looks like Somali to the eyes of the people who gave him the nickname.
Bottom line, the Somali name can be used for different reasons by different people and we should not see it negatively.
Of course, weirdos like @Qeelbax and others can turn everything into circus.