Broncos 2015 Salary Cap Outlook
overthecap.com
Brandon Marshall should be an exclusive rights player, which means he will be back for pennies on the dollar, so he should be open to a pretty reasonable extension. This might be the time for both sides to make a deal.
I think this is a bit early for a deal with Marshall, since he'll be an RFA a year from now. There's also the matter of finding out how well he operates within Wade Phillips' defense. Denver can get another year out of him at the $585K minimum, tender him at the first- or second-round level a year from now (at roughly $3.5M or $2.5M, respectively), and either work out an extension then, or address it after the 2016 season.