These are the dog days of summer.
That phrase typically entails the warmest part of the summer, and in most NFL cities, that is certainly true. However, for NFL players young and old, these are the days that try a man's endurance and his will. These are the days that, as the idiom goes, separate the men from the boys—the wheat from the chaff.
One mistake can be the end of a football career. An inadvertent injury can crush a young man's dreams. Moreover, it's possible to do absolutely everything correctly within one's power and still lose out because another guy is bigger, faster, stronger or simply younger.
It's survival of the fittest during the dog days of summer.
Throughout training camp and heading into the preseason's second week, some have shined and others have lost their luster. Click ahead to see who's standing out and who's sticking out like a sore thumb.