In my opinion Leafs should rarely be sellers. They simply need to manage the cap better so that they can spend as needed to improve.
I can see Barrie and even Kapanen traded, it wouldn't be a salary dump though, it would be to fill their gaps. This close to a playoff spot, you have to tweak and try and do something. Get in and anything is possible. At very least, it builds their experience and helps determine who wants it.
This is why when the all-star break came I created the post "should Dubas make a splash and wake up the troops"? I could see a team without that push needed and I felt something should be done to give them that push. They need more than one line, hell, really one player of late, to make the playoffs. Matthews is good, he isn't that good.
I say, make some trades and roll the dice a little. It probably wont be a splash now, but I would try to find one if possible. You know who your nucleus is. Can you surround that nucleus with the gamers needed to win? This team needs some balance, they are particular light in the back end, and that's not good when other teams feel they can will their way to the net.
The injuries change things from both sides of the ledger. The worst is just missing out on the post season because you couldn't find your balls to take some risk. It just has to be done, IF it is there. You aren't going to hand other GM's your talent, but you can find a win/win.
Win or lose, you can at least say you did something and figure it out in the offseason.