Hills was a fourth-round pick by Pittsburgh in the 2008 draft who had made just four appearances for the team over his first three years. The former University of Texas standout had been competing to be the Steelers' starting right guard during the preseason, but was beaten out by Doug Legursky.
Gilmore, a nine-year pro who signed with the Steelers in August, lost out to undrafted rookie Wesyle Saunders in the battle to be the team's backup blocking tight end. The 31-year-old was coming off a 13-catch, one-touchdown season with Tampa Bay.
Also cut on Saturday were cornerback Crezdon Butler, a fifth-round draft choice in 2010, punter Jeremy Kapinos and defensive lineman Jarrett Crittenton. Kapinos averaged 41.1 yards on 14 punts in last year's regular season after replacing injured starter Daniel Sepulveda with four games remaining.
Most of Pittsburgh's cuts took place on Friday, when the team released 21 players and put quarterback Byron Leftwich on injured reserve after the veteran fractured his left arm in a preseason game against Atlanta on August 27.
Cut loose were linebackers Baraka Atkins, Mario Harvey, Chris McCoy and Mortty Ivy, defensive lineman Corbin Bryant, defensive backs Brett Greenwood, Macho Harris, Donovan Warren and Da'Mon Cromartie-Smith, running backs James Johnson and John Clay, offensive linemen Colin Miller, Kyle Jolly, John Malecki, Trevis Turner and Keith Williams, wide receivers Armand Robinson, Wes Lyons and Tyler Grisham, tight end Jamie McCoy and kicker Swayze Waters.
Williams was a sixth-round selection out of Nebraska in this past year's draft.