Is it permissible for a Muslim player to wear a football team’s uniform that has a cross as its emblem, and what is the ruling on doctors, nurses, and military personnel working in entities that use the cross as an emblem on their official uniforms?

Professional sports should not be a Muslim's means of livelihood, nor is it permissible for him to wear clothes bearing a cross or a religious symbol of any disbelieving faith, just as it is not permissible for him to work in the armies of disbelieving countries.