ALAMEDA — The Raiders remain in the market for a defensive coordinator after Louisville’s Todd Grantham turned down a reported contract offer made by coach Jack Del Rio.

Grantham, according to the NFL Network, was offered a two-year contract Wednesday. Later that afternoon, ESPN reported Grantham had decided to remain at Louisville.

According to the Louisville Courier-Journal, Grantham is the fourth-highest-paid assistant coach in college football with an annual salary of nearly $1 million.

Former Atlanta Falcons coach Mike Smith, believed to be one of Del Rio’s initial targets, was inclined to take the season off, according to an ESPN report Monday.

The Raiders have yet to hire a defensive coordinator and a defensive line coach.

Del Rio’s search for a defensive coordinator has been mostly under the radar, with few names surfacing of candidates who have interviewed.

If the Raiders are targeting another current college coach, any selection would likely be after Feb. 4, the day recruits can sign national letters of intent.

Del Rio’s direct involvement with the defense will depend on the level of experience his coordinator has as a play-caller.

One possibility would be Ken Norton Jr., who coaches linebackers for the Seattle Seahawks and won’t be available for an interview until Monday.

Del Rio and Norton were teammates with the Dallas Cowboys from 1989-91 under coach Jimmy Johnson. “It just depends on the situation, who we acquire as the defensive coordinator, how I assess his play-calling abilities and readiness and those types of things,” Del Rio said at his introductory news conference. “If it were a veteran guy hired that I had complete trust to call game day, then I would let that go. If it’s a younger guy that is being groomed, I may help him along in that process.”