Cochran, 22, was eligible for last week's supplemental draft but was not selected. He will wear jersey No. 49 for the Packers.
Peterson, out of the University of New Hampshire, has professional experience with the Calgary Stampeders of the Canadian Football League, where he spent the past two seasons. Peterson played in 36 games, netting 99 receptions for 1,396 yards and seven touchdowns. The 6-0, 181-pound Windsor, Ontario native signed as a free agent with the New York Jets this past February, and was waived a month ago.
He will wear jersey No. 13.