He's doing that in a spread offense with Randy Moss on the outside. Slot receivers have a much easier job of getting open than #1 receivers as they generally going against LB'rs or nickel backs instead of a #1 CB with safety help. I don't know how anyone could watch Marshall and Welker play and come to the conclusion that Welker is the better receiver.
If you were building a team from scratch, both were available, and you needed a receiver - would you take Welker over Marshall?
