SANTA CLARA, Calif. -- Tramaine Brock is about to make his first NFL start, yet he is getting paid like he's already a solid starter.
The San Francisco 49ers have agreed to terms on a four-year, $16 million deal with the cornerback, who is set to be a free agent in March. The deal includes $7 million in guaranteed money.
Brock, an undrafted free agent from Belhaven, will start for the injured Tarell Brown on Monday night at Washington.
Brock has been outstanding this season as the nickel cornerback. He took over for an injured Nnamdi Asomugha in Week 4 and did not give up the job. Asomugha has since been released.
Brock has shined in an increased role this season, making a team-leading four interceptions to go with 18 tackles.
"Tramaine is a great example of what hard work and dedication can lead to," 49ers general manager Trent Baalke said in a statement. "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."
He had 16 tackles and a forced fumble last season, and shared the team lead with 15 tackles on special teams. His primary role was a special-teams standout until he recently received more responsibility in the secondary.
With Brock now signed for the immediate future, the 49ers can allow Chris Culliver -- the team's No. 3 cornerback last season -- plenty of time to recover from a season-ending knee injury suffered in August during training camp.
Brown sustained a rib injury during this past Sunday's 23-20 loss at New Orleans.
"He's just got to be ready to play every play not knowing he's got built-in breaks when we're in base like he had for the first however many games he was playing," defensive coordinator Vic Fangio said Friday of Brock. "There is a change, but it's just got to be a mental adjustment for him."
Information from The Associated Press was used in this report.