Cornerback Tramaine Brock signed a four-year contract extension with the San Francisco 49ers on Friday.
NFL.com reported that the new contract is worth $16 million, with $7 million guaranteed, and runs through the 2017 season.
Brock is preparing to make his first start on Monday night against the Washington Redskins in place of injured Tarell Brown. The undrafted free agent from Belhaven College has a team-leading four interceptions this season, including two against the Houston Texans on Oct. 6. One of those was returned for a touchdown.
"Tramaine is a great example of what hard work and dedication can lead to," 49ers general manager Trent Baalke said. "He has taken advantage of his opportunities since signing with our team as an undrafted free agent in 2010 and has certainly earned this extension. Extending the contracts of our young and talented players has always been, and will continue to be, one of our primary goals."
Brown suffered a rib injury in the 49ers' 23-20 loss to the New Orleans Saints in Week 11.
Brock is in his fourth year with the 49ers. After playing on special teams and as a reserve on defense, he moved past veteran Nnamdi Asomugha on the depth chart at cornerback this season.
In 40 career games, Brock has 34 tackles, six interceptions, 14 passes defensed and one touchdown. He also has 22 career tackles, including a team-leading 15 in 2012, and one forced fumble on special teams.