Wouldn't make much sense to do so as Ed points out in his blog, here is an excerpt
With the chance to reduce Mike Wallaceís salary from $2.742 million to $577,500 next Friday, the Steelers will pass, Iíve been told. It would make little sense for them to do that and perhaps increase the chances of Wallace not showing up for training camp and beyond if they did. Missing out on the weekly game check of $161,294 hurts a lot more than missing out on $33,971. Itís also not the way the Steelers do business. They want Wallace at training camp and available to open the regular season. Paying him $2 million less would not encourage that.