Complex sentence: His father, also Sergey, is former goalkeeper who coached his son while an assistant at FC Zenit Saint Petersburg, and both moved to FC Sokol-Saratov in 2005.
Split into simpler sentences: His father, also Sergey, is a former goalkeeper who coached his son while an assistant at FC Zenit Saint Petersburg. They both moved to FC Sokol-Saratov in 2005.