Which Pats WRs are on roster bubble?

Now that the New England Patriots have signed free agent Brandon LaFell and re-signed Julian Edelman, it appears that their WR corps is set for the time being. They did meet recently with free agent Kenny Britt and touched base with the Philadelphia Eagles about the availability of DeSean Jackson, but the consensus seems to be that they were simply doing their due diligence and are unlikely to land either of them.