Hightower, who was returning from knee surgery, was one of 23 players trimmed from the roster as the Redskins head into the regular season opener against the New Orleans Saints on Sept. 9.
Included in the tally was safety Tanard Jackson, who was suspended indefinitely by the NFL for violating the league's substance abuse policy.
Hightower's departure leaves the Redskins with three recent draft picks -- second-year players Evan Royster and Roy Helu Jr. and rookie Alfred Morris -- competing for a starting job that's been in flux since Clinton Portis was injured during the 2010 season.
The Redskins acquired Hightower in a trade with the Arizona Cardinals last year. He won the starting job out of training camp but played in only five games before tearing the ACL in his left knee. He re-signed with Washington in May and played in only one preseason game, getting five carries for 28 yards.
Among the bubble players making the cut was Brandon Banks, the high risk-high reward return man who can change games with his speed but is sometimes careless with the ball.
Shanahan said Banks needed to show improvement as a receiver to stay on the team, and Banks helped his cause with a 47-yard catch in Wednesday night's preseason finale against Tampa Bay.
The Redskins also cut quarterback Jonathan Crompton; receivers Anthony Armstrong and Terrence Austin; tight end Richard Quinn; offensive linemen Tom Compton, Grant Garner, Willie Smith and Erik Cook; defensive linemen Doug Worthington, Darrion Scott, Delvin Johnson and Marlon Favorite; linebackers Bryan Kehl, Markus White and Donnell Holt; and defensive backs Travon Bellamy, Brandyn Thompson and David Jones.
The Redskins also placed exempt defensive end Kentwan Balmer on the reserve-left squad list. Balmer left the team several weeks ago during training camp, having decided he no longer wanted to play football.
Information from The Associated Press was used in this report.