Some have jobs, others pursue careers. The difference between the two approaches has as much to do with attitude as it does anything else. If you say you have a career, that implies that you have conscientiously chosen this field of work and that each job you take helps you advance to higher and higher levels.
Careers involve long-range planning.
This distinction between having a job and having a career is an important one for athletes because too many of them haven't given enough thought to career choices. Some don't think about careers at all. Some halfheartedly pick something to study in school, but don't really plan to use it. Some focus solely on sports, but don't have a long-range strategy which extends beyond competition. If athletes don't think about careers until their competitive days are over, they aren't prepared for the change.