Just one day into his tenure with the Cincinnati Bengals, new head coach Marvin Lewis is wasting no time in assembling a staff, and could have his full complement of assistants in place by the end of the week.

The group, ESPN.com learned, will be a combination of new hires and some assistants retained from the staff of former head coach Dick LeBeau.

"You want a mix of young and old," Lewis said from Mobile, Ala., site of the annual Senior Bowl all-star game. "I want good teachers, the best that I can find out there."

Lewis has already decided on the two coordinator positions, key posts for any staff, but particularly for a first-time head coach. Offensive coordinator Bob Bratkowski, with the Bengals since 2001, will be retained. The team has reached agreement with current longtime Atlanta Falcons secondary coach Emmitt Thomas, ESPN.com learned, to be the defensive coordinator.

One of the league's most respected defensive assistants, Thomas has been a coordinator in the past with Philadelphia, Green Bay and Minnesota. He and Lewis have been longtime friends and, for many years, it seemed Thomas might one day be a head coach candidate.

The new defensive line coach is Jay Hayes, who has never before coached the position, and most recently was Minnesota's special teams coach.

"I think it is a great opportunity for Jay to be able to work with a person he has a long history with," Vikings coach Mike Tice told the Minneapolis Star Tribune on Wednesday. "I didn't want to stand in the way of that. I'm very happy for him."

Cornerbacks coach Kevin Coyle and running backs coach Jim Anderson, who was one of five candidates interviewed for the head coach position, will be retained. Lewis on Wednesday spoke with current offensive line assistant Paul Alexander about staying on but there was no resolution of his status. Alexander was recently interviewed by the Buffalo Bills.

The Bengals don't intend to announce any hirings until the entire staff is assembled.

Len Pasquarelli is a senior writer for ESPN.com.