The Falcons elected to sign Kerin to their practice squad after the session.
Grasu, 27, is a former third-round pick of the Bears back in 2015. He was in the final year of his four-year, $3.44 million contract that included $814,855 guaranteed and set to make a base salary of $705,000 for the 2018 season when the Bears waived him coming out of the preseason.
Since becoming a free agent, Grasu has worked out for the Ravens and Vikings.
In 2017, Grasu appeared in six games for the Bears.