Clausen made two starts and appeared in six games over the past two seasons for Chicago. That included a forgettable 26-0 loss at Seattle in September that saw him throw for just 63 yards filling in for the injured Cutler and the Bears punt on all 10 possessions while falling to 0-3.
Coach John Fox said the Bears waived Clausen because other teams were showing interest in Fales, a sixth-round draft pick out of San Jose State in 2014.
Chicago (4-6), coming off a loss to Denver, visits Green Bay (7-3) on Thursday.
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