I like the idea of getting a better-than-average journeyman vet "right now."
Card went out and got such a player in Ross Gandy for the LT who played well enough to help that Warner-driven team reach the Super Bowl. Gandy was no Whitworth - but I bring him up to support the idea of trading for a vet who can play consistently.
Besides, if real plug-and-play offensive lineman, all-pro written all over him is targeted and available when the Rams are on the board, they'll probably draft a speedy little wideout instead.