Mike Mayock has long had a “ready list” of candidates to join his staff if he ever landed in an NFL front office. The new Raiders general manager wasted no time adding a name.

The Raiders will hire former Indianapolis Colts GM Ryan Grigson, Pro Football Talk reported Friday morning, citing a league source. The website said it was a “done deal.”

This news comes two days after the team fired director of player personnel Joey Clinkscales, who was former GM Reggie McKenzie’s right-hand man. Grigson’s title remains uncertain at this time -- the Raiders have not made an announcement -- but it’s logical Grigson would slip into Clinkscales’ former spot in the personnel department.

Mayock enters his new job with tremendous experience analyzing college prospects, and he has done some pro scouting, but he admittedly needs help with the daily mechanics of being a GM.

Grigson has experience with the day-to-day duties of running a team and coordinating efforts between the college and pro scouts, the coaching staff and the salary cap experts.

Grigson was the Colts GM from 2012 to 2016, with experience as a scout since 1998. He also was Philadelphia Eagles director of player personnel from 2010 to 2011. His tenure with the Colts was a struggle, and he was widely criticized for some draft picks and free-agent signings as the head man, but it wasn’t all bad.

Grigson was named NFL Executive of the Year after the 2012 season, during which he carried out a radical roster reconstruction. The Colts eventually went downhill, and he was let go in early 2017.

Grigson spent 2017 in Cleveland and 2018 in Seattle in advisory roles. He will be part of a greater operation with the Raiders.

Grigson would support Mayock and the personnel department, helping to present head coach/football czar Jon Gruden with quality information pertinent to making a smart final decision.

Gruden has final say on all Raiders football matters.

Grigson would come in early and help the Raiders as they head toward a 2019 NFL Draft where they have three first-round picks and four selections in the top 35. They also have significant salary-cap space to spend on free agents, without big-money extensions coming due in future seasons.