With the NHL trade deadline right around the corner, the Pittsburgh Penguins and other contenders have tough circumstances. The salary cap is tight. Many teams are within striking distance (or think they are and don't want to admit quitting on the season by selling off players) so there isn't a big supply of players.
In a perfect world, the Penguins would probably love to add a depth defenseman. Their defense has had it's share of injuries this year, and the number 7 defenseman in the organization now is Chad Ruhwedel. With all due respect to Ruhwedel, that means any injury to the top-6 players puts Pittsburgh in the treacherous territory of dressing a player for playoff games who is probably not suited for NHL playoff action.