Complex sentence: He played nine seasons in the major leagues, from 1977 to 1985, for the Oakland Athletics, Milwaukee Brewers, and California Angels, where he was primarily a shortstop, although he also played at third base and second base.
Split into simpler sentences: He played nine seasons in the major leagues, from 1977 to 1985, for the Oakland Athletics, Milwaukee Brewers, and California Angels. He was primarily a shortstop, but also played at third base and second base.