Broncos 2015 Salary Cap Outlook
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.