Bears QB Justin Fields to start preseason finale Saturday vs. Titans

Rookie quarterback Justin Fields will start the Bears’ third preseason game Saturday against the Titans in Nashville, Tennessee, coach Matt Nagy said Tuesday.

But it’s not a ‘‘dress rehearsal,’’ like the third preseason game used to be. It’s not even an audition. Andy Dalton will start the regular-season opener against the Rams on Sept. 12 in Inglewood, California, no matter what Fields does against the Titans. Dalton, in fact, won’t play against the Titans.

Still, for the heralded Fields, it will be a chance to give Nagy and the coaching staff a better indication of his preparedness to start in place of Dalton whenever the time comes.

Fields will play ‘‘probably two quarters,’’ Nagy said. The starting offensive line will play with him, likely with left tackle Jason Peters and right tackle Germain Ifedi playing for the first time this preseason. But starting skill-position players aren’t expected to play.

‘‘For us, it’s all about him just getting better,’’ Nagy said of Fields. ‘‘We just want to see him play hard, play well. The variables are different . . . just like Andy hasn’t been out there with some of those [starting] receivers. So all I want to see from him is just play a good game and keep the big picture in mind for all of us.’’

It is unknown whether Fields will face the Titans’ first-team defense. Titans coach Mike Vrabel, who has rested many of his starters in the first two preseason games, indicated his first-teamers might get at least token snaps — and perhaps more — against the Bears.

Nagy’s announcement that Fields will start against the Titans is exciting for Bears fans eager for him to start as soon as possible. But Nagy downplayed the short-term significance, especially with few starters participating.

‘‘You’re gonna see a direction more like the old-school fourth preseason game,’’ he said, referring to what traditionally has been a showcase for reserves on the fringe of the roster.

For Fields, who has managed the sometimes-awkward quarterback situation well so far, starting against the Titans and playing with the first-team offensive line is just another chance to grow in Nagy’s system and get into a groove with likely an entire half of snaps.

‘‘That’s one of the biggest parts, playing and finding that rhythm,’’ Fields said. ‘‘I’m going to approach this game like I’ve approached the last two games: getting in the game, moving the ball down the field and trying to score a touchdown every drive.’’

Fields sparked excitement in his preseason debut against the Dolphins by completing 14 of 20 passes for 142 yards with a touchdown and no interceptions for a 106.7 passer rating and adding an eight-yard touchdown run. He was less successful against the Bills (9-for-19 for 80 yards, no touchdowns or interceptions for a 59.1 rating), but he still showed off his speed with four carries for 46 yards.

‘‘I think I’m where I want to be,’’ Fields said when asked about his progress. ‘‘I’m just focused on every day . . . getting better. Learn from mistakes in practice — bad plays, good plays — and continue to get better every day.’’

But there’s nothing like an actual game. That makes the game against the Titans invaluable not only for Fields, but for Nagy evaluating his readiness to play in the regular season.

‘‘The biggest difference between games and practice is the actual [defensive] line coming to hit you,’’ Fields said. ‘‘In practice, the d-line is told not to be around the quarterback. But actually facing that in-game pressure and having to throw with pressure in your face is the biggest difference between a game and practice.’’

The first two preseason games haven’t exposed any particular areas that need improvement.

‘‘Not one specific thing,’’ Fields said. ‘‘I’m just going to make sure I do my job the correct way, and hopefully we come out with a [victory].’’