Byrd has Limited no Trade clause

"The Rockies tried desperately to acquire a fifth starter before the non-waiver deadline but couldn't match-up with the Mariners for Jarrod Washburn or the Nationals for Tim Redding; and Paul Byrd had Colorado on his no-trade list. The Rockies will continue to look for a starter via waiver wire claims."

Thanks to mlbtraderumors.com

I didnt feel Byrd was going to be a good fit there, (like most pitchers) He must not feel like its a place he wants to pitch either.