Christian Rojas is set to make his Chilean debut once again after he quit in 2001. A former defender who quit playing in 2001, aged 25, because of a knee injury, Rojas is part of an exclusive group of top players who have made a successful transition to refereeing.

Rojas, whose only club was first division Cobresal, has spent the past few seasons officiating in the second division but has been promoted to the top flight this season and makes his debut this weekend.

"This (job) always appealed to me but I had two right knee operations (for torn ligaments) that made it difficult for me to continue playing," Rojas told Reuters in an interview.