The 49ers have reached an agreement with free-agent running back Tim Hightower, general manager John Lynch tweeted Saturday.
Hightower, 30, has made one of the NFL's most remarkable comebacks during the past two years with the Saints after spending three-plus years out of the league because of a knee injury.
Hightower tweeted thanks to the Saints for giving him a chance "when no one else would."
Hightower, who began his career with the Cardinals, suffered a torn ACL after being traded to the Redskins in 2011. Doctors later discovered an infection that was stunting his recovery.
The 6-foot, 220-pounder has combined for 923 rushing yards, 329 receiving yards and nine touchdowns in the past two years as a backup to Mark Ingram. And he has shown the ability to take over as an every-down back when needed, with a pair of 100-yard rushing games.
Hightower has a total of 2,977 rushing yards, 1,208 receiving yards and 34 touchdowns in six seasons.
The 49ers also re-signedDuJuan Harrisearlier this week. Hightower was with Shanahan in Washington in 2011 and is expected to compete and offer depth behindCarlos Hyde.
ESPN's Mike Triplett and Nick Wagoner contributed to this report.