Harris is a 6-foot-1, 237-pound rookie from Louisiana-Lafeyette who went undrafted this year and signed with the Green Bay Packers. He appeared in six games for Green Bay this season, totaling four rushes for 19 yards. In the preseason, he totaled 21 carries for 85 yards as he went from long shot, to on the bubble, to the 53-man roster.
He was released by the Packers on Dec. 3.
In addition to working out Harris, the Patriots signed running back Montee Ball to their practice squad, as the focus at the position is tied to the left hip injury sustained by LeGarrette Blount on Sunday night. Blount was walking with the aid of crutches on Tuesday.
As for Snyder, he is a rookie from Rutgers who signed with the Detroit Lions after the draft. He broke his hand in the preseason and was placed on injured reserve before being officially waived by the team on Oct. 13. He spent a week on the 49ers' practice squad in late November.