Anderson told The Associated Press he has agreed to a one-year deal and that he will sign the contract later Wednesday. Financial details were not disclosed.
"I'm excited to come back be a part of such a great locker room," Anderson said. "It's a team that I feel is on the rise. We have some work to do but we feel like we ended on a high note last season."
Anderson hasn't seen much action in his two previous seasons with Carolina -- attempting only four passes -- because Newton has been so durable. However, the eight-year pro gives the Panthers the veteran presence they want from a No. 2 quarterback.
In another deal, the Panthers announced they have signed 10-year NFL veteran cornerback Drayton Florence, a free agent from the Detroit Lions. He also signed a one-year deal, although terms were not disclosed.
Florence, 32, brings some experience to an otherwise young group of cornerbacks.
A 10-year NFL veteran, Florence played in eight games with three starts for the Lions in 2012 after being released by the Denver Broncos at the end of the preseason. Florence entered the NFL from Tuskegee as a second-round draft choice of the San Diego Chargers.
He has played in 143 games with 99 starts for San Diego (2003-07), Jacksonville (2008), Buffalo (2009-11) and Detroit (2012). He has career regular-season totals of 444 tackles, 18 interceptions and 96 passes defensed.
The Panthers did lose a free agent on Wednesday as backup tight end Gary Barnidge signed with the Cleveland Browns. Barnidge's decision came one day after the Panthers re-signed their other backup tight end Ben Hartsock.