Harbaugh could be back at the 49ers practice facility on Friday, according to the team, which added that no other information is currently available. Assistant head coach and special teams coordinator Brad Seely assumed Harbaugh's duties at Thursday's practice.
In a season and a half under Harbaugh, the 49ers are 19-5-1. The team lost in the 2012 NFC Championship Game to the New York Giants to end Harbaugh's first season at the helm.
As a player, Harbaugh spent parts of 14 seasons as a quarterback, half of which came with the Bears. He took over starting duties in Chicago in 1990, and proceeded to hold that role for four seasons, throwing for nearly 10,000 yards and 45 touchdowns. Harbaugh also threw 45 interceptions during that period.