Dallascowboys.com writers recently took question and one was about rookie WR Devin Street:
Question: I haven't heard much mention about Devin Street. How is he doing at camp? Where do you think he will fit in?
Bryan Broaddus: I have been much more impressed with what Street has been able to do in these practices as opposed to how he has played in the OTAs and minicamps. Right now I would think that he is looking at the fourth spot with the potential to see some work with Bryant and Williams. He has done a nice job with his route running and has been consistent with his hands. He is looking comfortable with all the opportunities in which they have put in his direction.
David Helman: All credit due to Cole Beasley. I thought heading into camp that Street was a serious contender to win the slot spot and take playing time away from Beasley, and that just hasn’t been the case. To this point, Beasley has looked impressive and I’d be stunned to see anyone unseat him. That’s not a knock on Street at all. He has looked good in practice and, just like in OTAs, my main takeaway from watching him play is his versatility within the formation. It will be fun to watch him get some snaps in San Diego.
Sounds like Street will be the fourth WR with limited work. He could be struggling a bit in the slot because he's more of an outside WR, so it appears Beasley slot role is safe right now.