Tennant was claimed via waivers on Saturday, while Hilliard was among the final cuts of the Minnesota Vikings prior to the deadline to finalize 53-man rosters.
A sixth-round pick in 2008 of the Miami Dolphins, Hilliard (5-foot-11, 240 pounds) has career totals of 39 carries for 130 yards and two touchdowns. He was used occasionally in a fullback-type role during his three active seasons with the Dolphins, and also played on special teams.
The Patriots were carrying four running backs prior to the signing of Hilliard, although they do not have a true fullback on the roster. Given his size and previous experience, it's possible that Hilliard could serve in a hybrid running back/fullback role.
Hilliard was one of 10 players to work out for the team on Tuesday, along with: defensive back Eric Frampton, linebacker Jerrell Harris, defensive back Devin Holland, defensive back Dante Hughes, wide receiver Jaymar Johnson, quarterback Mike Kafka, wide receiver Tysson Poots, defensive back Cyhl Quarles and linebacker Jason Williams.