The New England Patriots acquired linebacker Jonathan Bostic from the Chicago Bears for a 2016 6th round pick. One year later, the Patriots have sent Bostic to the Detroit Lions for a conditional 2017 7th round pick.
New England was probably going to cut Bostic anyways, so receiving a conditional 2017 7th round pick (likely linked to whether or not Bostic makes the team) is the best compensation the team could receive- and it's basically for free. A conditional 7th rounder is essentially a legal way to bypass waivers so a team can obtain a roster bubble player.
Lions general manager Bob Quinn, who served as the Patriots director of pro scouting and was likely the key driver behind the Patriots acquisition of Bostic in the first place, was happy to get a linebacker for camp with potential starter upside.
Bostic was the 5th linebacker on the Patriots depth chart in 2015, behind Dont'a Hightower, Jamie Collins, Jerod Mayo, and Jonathan Freeny. Former Bears linebacker Shea McClellin joined the Patriots in free agency, meaning that Bostic was not going to be any better than the 5th linebacker in 2016.
The Patriots were also happy to send Bostic and his $942k cap hit away early in the offseason because the linebacker also has a $100,000 workout bonus in his contract.
Since Bostic was purely a special teams player in 2015, the Patriots felt comfortable replacing him with a cheaper alternative. Free agent acquisition Ramon Humber has a $676k cap hit in 2016, with 6th round picks Kamu Grugier-Hill ($475k cap hit) and Elandon Roberts ($475k cap hit) also offering cheaper deals.
Basically, the Patriots are saving up to $500,000 in cap space with this trade, if we're looking at Bostic's potential replacement options- and if Bostic makes the Lions roster, the Patriots will regain their 2017 7th round pick that was lost while acquiring tight end Michael Williams from the Lions. Along with the trade to acquire the 2017 4th round pick from the Seahawks, it's clear that head coach Bill Belichick is doing whatever he can to collect his 2017 draft capital.
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