Holley's best asset is the ability to go up for the ball, he has very good hops. Holley is competing w/Stanback (who is faster, more experienced in system and versatile_returner & wildcat QB), Ogletree (better hands, better route runner & much greater speed) and Johnson (can play the slot, more WR experience, versatile_returner & wildcat QB) for the last WR slot (IF Cowboys carry 5). And Holley is still learning not only the position, but the game of football. Not to mention his hands are iffy. Holley's only hope is if a couple of guys get injured, otherwise there is no way he dislodges either Hurd (experienced in system, great hands, can play slot, very good STer), Crayton (great hands, proven, slot, returner) or Austin (big play guy, dynamic returner, speed).
Coach Joe said it best, "you (Mike) said it, the best way to get on this team is to dominate on ST, and Hawkins is the best STer". Holley on the other hand is average to mediocre in return coverage and lacks both the long speed and quickness to be a returner.