Bad news for rookie tackle Robert Bewster. From Mickey Spags:

Third-round draft choice Robert Brewster has suffered a torn pectoral muscle while lifting weights in the post-minicamp training program, Cowboys owner Jerry Jones confirmed, and the subsequent surgery to repair the injury leaves him unavailable for the start of training camp. The Cowboys are unsure if the offensive lineman from Ball State can return in time to become active for the 2009 season.

[snip]

The Cowboys could place Brewster on injured reserve if they think he has no chance of getting back this season, which would open up a roster spot. Or they can buy some time by placing him on PUP (physically unable to perform) before the cut to 53 which would afford him another six to 10 weeks of recovery time during the season without counting against the 53-man roster or being lost for the year.