Complex sentence: Telus Field is a unique baseball stadium in that the infield uses FieldTurf but the outfield is natural grass; originally AstroTurf was used but it has since been recently replaced with the more modern type of turf.
Split into simpler sentences: Telus Field is a unique baseball stadium in that the infield uses Fieldturf but the outfield is natural grass. Originally AstroTurf was used but it has since been recently replaced with the more modern type of turf.