Lehner might not be tradeable at this point as he's still suffering headaches from a concussion suffered earlier this season.
In a REALLY brief update....
http://fantasynews.cbssports.com/fantasyhockey/update/25167442/sens-lehner-not-over-concussion-yet/sens-lehner-not-over-concussion-yet
He was injured Feb 16 so the update in that link was at the 2.5 month mark. I'm sure he'll get better but I think most teams will be very leery of acquiring him now.