Complex sentence: He has played in Major League Baseball (MLB) for the Seattle Mariners and Toronto Blue Jays, and was nicknamed "The Condor" by Dave Sims, who attributed the origin of it to Lee Tinsley.
Split into simpler sentences: He has played in MLB for the Seattle Mariners and Toronto Blue Jays. He was nicknamed "The Condor" by Dave Sims, who attributed the origin of it to Lee Tinsley.