Joey Harrington remains under contract with Detroit, but Lions management has given him permission to seek a trade, and the quarterback will visit Cincinnati today.
Harrington was expected to make a quick visit Tuesday night to Miami.
The Bengals are searching for a quarterback who could start in case Carson Palmer's surgically repaired left knee prevents him from opening the season.
Palmer and Harrington both are represented by agent David Dunn, who has a productive relationship with the Bengals and coach Marvin Lewis. The Bengals would have to trade for Harrington, and the Lions, wanting to dump his contract, probably would accept a sixth-round pick. Harrington then would rework his contract with his new team.
Kansas City and Seattle also are interested in possibly trading for Harrington, who has started 55 of his 58 NFL games. He has 60 touchdowns and 62 interceptions and has thrown for more than 10,000 yards.
He started 11 of 12 games last season for the Lions, throwing for 12 touchdowns and 12 interceptions and more than 2,000 yards. Harrington became embroiled in a quarterback controversy in Detroit with Jeff Garcia.
Lewis said Tuesday the Bengals might not add another quarterback until May. The team has been focused on former Rams backup Jamie Martin and Anthony Wright, formerly of the Ravens.