Chargers general manager Tom Telesco was in the Colts' front office when they took Brown in the first round of the 2009 draft.
Brown ran 102 times for 537 yards and a career-high six touchdowns in 2013. In five seasons he has 551 carries for 2,377 yards and 17 touchdowns.
Tuesday's deal came on the first day of free agency.
Talk about the signing of running back Donald Brown inside the message boards.
Brown Agrees to 3-Year Deal
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