Salas came into the league as a 4th round pick of the Rams in 2011, but his rookie season was cut short when he broke his leg after 6 games. Prior to this year, the Patriots traded a 7th round pick for him, but he only appeared in one game this year. He was waived today when the Pats activated rookie tackle Markus Zusevics.
Here's what ESPN had to say about Salas prior to the draft.
Salas has above-average downfield speed but takes a bit of time to generate his speed on the release. He is not as quick and explosive as necessary to be effective uncovering when faced with solid man coverage corners. He needs to be a bit crisper on his routes, but he does a solid job of reading coverages and finding lanes against zone schemes. He is a natural catcher who can reach out and pluck the ball in all areas.
In college at Hawaii, Salas was primarily used in the slot and was a YAC monster. The Rainbows run a spread offense, so it really suits a guy like that and his numbers in school reflect it.
In his junior year, Salas caught a ridiculous 106 passes for 1,590 yards and 8 TDs. He would actually improve that in his senior year catching 119 passes for 1,889 yards and 14 TDs. Even with numbers inflated by the spread, that's impressive. He's actually graduated with the 6th highest receiving yardage total in NFL history.
With Jason Avant still on the shelf and frankly not offering anything special for a few years now, the Eagles could certainly use help in the slot. Riley Cooper took snaps there last week and while he was solid, it's clear that he's not built to play in the slot, whereas Salas is a specialist there.
He also has some experience returning kicks, but hasn't been particularly special there.