That's notable because, after trading Kiko Alonso, the Bills have a need for depth at linebacker.
Here is their current depth chart at their two off-the-line linebacker spots:
If Rex Ryan's history with the New York Jets is any indication, the Bills could get by with that group. Ryan's defense relies more on defensive backs than linebackers in sub packages, and over the past two seasons, he's only carried three off-the-line linebackers consistently -- David Harris, Demario Davis and Nick Bellore.
The Bills can go in one of three main directions here.
First, they could attempt to re-sign Spikes at a discount. Spikes hasn't generated much interest through the first two weeks of free agency, which could make him more affordable. He'd be an upgrade over Powell in a part-time, run-stopping role. However, the Bills could still have trouble fitting in Spikes' salary, since they'll have very little cap space remaining once their deal with Charles Clay officially goes on their books.
Second, the Bills could re-sign either Dean or Sylvester to help on special teams. That would come at a lesser cost than Spikes but wouldn't add much depth on defense, potentially forcing Powell into a starting role if Bradham or Brown is injured.
Third, the Bills could opt to bypass adding a free agent and instead draft a linebacker this spring. That's riskier, since they'd need to have the right player on the board at the right time. But the contract would come out of the Bills' rookie pool, which would benefit the cap-strapped Bills from a financial perspective.
The wild card in this analysis is 2014 seventh-round pick Randell Johnson, who split time between defensive end and linebacker in college. Johnson briefly ran with the Bills' defensive ends in OTAs last season before seeing time at 4-3 outside linebacker in the preseason.
In Ryan's scheme, Johnson projects to the 'Sam' linebacker spot (where Manny Lawson and potentially Jerry Hughes will be stationed), but it's not out of the question for him to play more in space as either a 'Mike' or 'Will' linebacker.