Not a big White fan, so I hope we pick some vet up. Right now the top 3 on my list are Helu, Bush, and Thomas. If they can pass block, they would be an adequate replacement for Vereen.
I would have loved to have had him back, but this was not a good cap year for paying market prices for situational skill players. You can't keep everyone, and fortunately the Pats lost a player at a position that could be the most well stocked in the league.
Just a thought. IIRC Josh Boyce was known in college for his YAC. Since Vereen was 70-30 more a receiver than RB, how about shifting Boyce to RB and let him see what he could do there. Right now he seems stuck behind Edelman and DA