May 12, 2009 10:05 AM EST

White Sox pitcher Jose Contreras has cleared waivers and been sent to Triple-A Charlotte in order to work on his forkball.

"The lack of his forkball is the thing we got to get right," pitching coach Don Cooper said Monday.

Contreras, who was 0-5 with an 8.19 ERA in six starts, had to approve the demotion because he has five years of service in the major leagues.

"I tip my hat to Jose," manager Ozzie Guillen said. "He could be home right now collecting the White Sox's money. He works hard, and I have more respect for him than I ever have. Not too many players say, 'Listen, I need to do this to help you guys.' Other guys would say, 'I don't care. I make my money. I'll be home. I'll be in the bullpen and pitch once a month. Who cares?'

"He worries about this ballclub and cares about this ballclub. He's in my top three most respected players I ever have. You say that and mean that, and you tip your hat to him."

Via Chicago Tribune