The Titans unleashed an aggressive, turnover-forcing defense last weekend against the Carolina Panthers.It was a welcome sight for a team trying to make the leap from 9-7 to reach the playoffs for the first time in nine years.The Titans will look to give their defense one more tune-up when they play their third preseason game Sunday against the Chicago Bears. Kickoff is set for noon at Nissan Stadium in Nashville.With third-year pro Marcus Mariotta quarterbacking an offense with an array of weapons, many analysts believe it’s the Titans defense which holds the key to the team’s success. The D looked up to the test last weekend.The Titans forced three turnovers against the Panthers, their second preseason opponent.