66857
Ronaldo clashed with a teammate , striker Ruud van Nistelrooy , who took offence at the winger 's showboating style of play .
 Ronaldo, Ruud van Nistelrooy
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Ronaldo, Ruud van Nistelrooy