As the Astros continue to win games and prove that their hot start wasn't a fluke, they're quickly becoming one of the most prominently talked about teams in the lead up to the July 31st trade deadline. They've been linked to several starters like Scott Kazmir, Johnny Cueto, and Aaron Harang, but the most intriguing name is undoubtedly Cole Hamels.
He has the ability to block a trade to 20 teams, and a person close to him suggested that he wasn't sure if Hamels would accept a deal to Houston, "despite their impressive start and wildly improving future." That same person threw in the caveat of "you never know", but it's ultimately the biggest hurdle for the Astros to clear.
The Phillies' willingness to eat a portion of Hamels' contract is a factor working in Houston's favor, as they "aren't inclined to pay any one player $24 million annually". The Astros have a loaded farm system, and are seemingly years ahead of their expected contention schedule; making them an attractive destination.
Über prospect Carlos Correa is likely set to make his major league debut some point in the near future (once the super-two cutoff has passed), and Mark Appel is still working his way through AA. While Correa is untouchable in any trade talks, the Astros have the pieces to acquire Hamels without mortgaging their future.
Someone close with Houston's thinking said that GM Jeff Lunhow has his sights set on a No. 1 or 2 type starter, or at the very least, a pitcher "who could qualify to pitch games '1 through 3' in a hypothetical playoff rotation". Special Assistant Nolan Ryan has also been said to be a huge fan of the lefty, and could potentially make Houston a more attractive landing spot. Teaming Hamels with Dallas Keuchel would immediately give the Astros one of the best one two punches in baseball, and set them up well for October.
Jon Heyman notes that if the Astros can't acquire Hamels (whether it be because he won't approve a trade or Ruben Amaro doesn't agree on a package) there are other options for the team. Jeff Samardzija, Kyle Lohse, Dillon Gee, and possibly Bartolo Colon are all names on Houston's radar. It's all but a foregone conclusion that Houston is going to trade for a starter, but who that will be remains the question.