Complex sentence: Niño's injury woes were recurrent in 2008--09, as he was forced to miss 19 league matches; he retired from football with immediate effect at the season's end, amassing professional totals of 264 games and eight goals.
Split into simpler sentences: Niño's injury woes were recurrent in 2008--09, as he was forced to miss 19 league matches. He retired from football with immediate effect at the season's end, amassing professional totals of 264 games and eight goals.