Take this with a grain of salt .. I figured I'd share this since this rumor popped up today so the cat is basically out of the bag.
A person I know that's pretty vested in the organization and has some pretty strong sources, basically told me the FO is trying to swap a WR, then restructure one of their bigger deals (possibly Mebane with an extension.. or by shuffling money for Thomas/Sherman) to fit in Alex Mack. He's a guy they covet basically. However, the deal would not be cheap (think 1st round pick). He said the WR's being mentioned as possibly being included in the deal are Matthews or Kearse.
So again... grain of salt here.. the rumor has validity it seems.. but it doesn't necessarily mean it is anywhere close to happening, especially with the cap restrictions.. the FO would have to do some other things to fit in a salary of a veteran OL.