Sproles agreed to a four-year, $14 million deal with $6 million guaranteed, a league source told NFL Network insider Jason La Canfora. Sproles can't sign the deal until Friday.
The Saints added Sproles on the same day they traded Reggie Bush to the Miami Dolphins. Like Bush, Sproles has proven an ability to produce big gains as a runner, receiver and return man. He has two career touchdowns on kickoff returns and two scores on punt returns.
In each of his seasons except 2006, when he was injured, Sproles has surpassed 1,000 yards on kick returns.
The Associated Press contributed to this report.