The biggest move of the bunch would probably have to be the placing of cornerback Jabari Price on the injured reserve list, ending his season. Price missed the first two games of the season as a part of his punishment for a DUI he received after the 2014 season finale. He came back for the third game of the season, but had missed several games with a shoulder issue. Price was probably going to have trouble cracking the cornerback rotation with the pending return of Josh Robinson, and now he's done until 2016.
The team also brought back a familiar face, bringing linebacker Brandon Watts back onto the 53-man roster from the practice squad. Watts, like Price, was a seventh-round pick of the Vikings in the 2014 NFL Draft, and saw limited time for the Vikings towards the end of the 2014 season. He was cut after the 2015 preseason and brought back to the practice squad.
The Vikings also made some other practice squad moves. They brought back fullback Blake Renaud, an undrafted free agent out of Boise State who spent the preseason with Minnesota. They also brought in a new face in former Washington Redskins' linebacker Terrance Plummer. Plummer was with the Redskins this preseason as an undrafted free agent out of Central Florida. He was part of Washington's final cuts, but was brought back to the practice squad and elevated to the Redskins' 53-man roster on 19 September. He played in three games with the Redskins before being released.
To accommodate both of those players on the practice squad, in addition to elevating Watts, the team cut ties (again) with wide receiver Donte Foster.