In limited action during three games this season, Clausen has completed 33 percent of his passes for 42 yards and zero touchdowns.
The Bears signed Clausen in June after he spent the previous four seasons with the Panthers.
Clausen, a second-round pick in the 2010 draft out of Notre Dame, completed 52.5 percent of his passes for 1,558 yards and three touchdowns with nine interceptions in his rookie season.
Cam Newton took over as Carolina's starting quarterback in 2011 after the team selected him with the No. 1 pick in that year's draft.
The Panthers waived Clausen prior to the 2013 season and was placed on injured reserve after going unclaimed.
The 27-year-old Clausen takes over as the Bears' starter with the team having lost three consecutive games.
In January, the Bears reached a seven-year contract extension with Jay Cutler, who has struggled this season. A recent report said that the team has "buyer's remorse" about the deal. Cutler has thrown a league-high 18 interceptions this season.
The Bears are 5-9 and in last place in the NFC North.
- Chris Johnson