General manager John Lynch made the announcement on Twitter: "#Faithful - We've agreed to terms w/ @Tim_Hightower. We got better this week with Tim and @DuJuan_Harris. #brickbybrick #welcometothefamily."
Hightower, 30, joins running back DuJuan Harris, who re-signed with the 49ers, as backups to starter Carlos Hyde.
The 6-foot, 220-pound Hightower spent the last two seasons with the New Orleans Saints after being off the field for three-plus years because of a knee injury. He played in eight games for the Saints in 2015, his first appearances since the 2011 season.
Hightower had a combined 923 rushing yards, 329 receiving yards and nine touchdowns in the last two years as a backup to Mark Ingram.
- - -
Drew Brees is heading into the final year of his contract, but the 38-year-old New Orleans Saints quarterback insists he is not concerned about getting an extension.
Brees previously said he is not seeking a new deal this offseason. He said waiting until the end of the season is in the best interest of himself and the team.
"I'm just trying to stress the sense of urgency," Brees told the New Orleans Times-Picayune. "I'm just so focused on this year, just being in the moment, not thinking about anything beyond this and taking every other year as it comes. But, also, we're building something here. We are building something. I feel like we have a window of opportunity."
Brees understands the Saints could select a quarterback in this year's draft to eventually replace him as the starter.
- - -
The Vikings are bringing Keenum in to serve as the backup to Sam Bradford this season.
The health of former starter Teddy Bridgewater remains in question after he suffered broken left leg and torn ACL in August. Bridgewater is uncertain when he will return.
Keenum began last season as the starter for the Los Angeles Rams before being replaced by number one overall pick Jared Goff. Keenum started nine games and passed for 2,201 yards, nine touchdowns and 11 interceptions. (Editing by Gene Cherry)