Preparation a trademark for Mitch Trubisky

When Bears quarterback Mitch Trubisky was a redshirt freshman at North Carolina, he had his ups and downs in spot duty behind starter Marquise Williams (touchdown passes against Liberty and East Carolina, interceptions in three of his first five appearances) but seemed to learn well.

After two weeks of not playing at all, Trubisky was thrown into a key game at Virginia on a moment’s notice when Williams had to sit out a play after losing his helmet on a sack. Facing a third-and-15 in his first real moment since high school, Trubisky threw a 16-yard touchdown pass with 4:05 left to make the difference in the Tar Heels’ 28-27 victory.

It wasn’t exactly a watershed moment in Trubisky’s career — he lost another battle for the starting job to Williams the next season — but it was an indication the kid was a quick study who didn’t need a long lead time to succeed.

Trubisky similarly came through three times the next season. In a scoreless game against North Carolina State, he replaced Williams again because of the helmet issue and threw a five-yard touchdown pass to give North Carolina a 7-0 lead. In the Atlantic Coast Conference championship game against Clemson, he came in for one play and threw a 16-yard pass for a first down that helped set up a field goal that gave the Tar Heels a 3-0 lead. Earlier that season, he took over for a struggling Williams and threw four touchdown passes in a victory against Delaware.

‘‘Just go in there and have fun with it,’’ Trubisky, who will make his first NFL start Monday against the Vikings, said when he was asked how he was able to succeed in those bit-part moments. ‘‘Control what I can control and do my job.

‘‘It doesn’t matter how many snaps you get or when you come into the game. You’re put in there for a reason, and that’s to do your job So when you go in there, you’ve got to do it and make plays.’’

For what it’s worth, Trubisky’s 226.4 passer-efficiency rating in 2015 is the best in college football for a quarterback with fewer than 100 passes but more than 20 since at least 2000. Besides having the physical skills, Trubisky has shown he pays attention, learns well and has an intuition about the position — all good traits for a quarterback built to survive whatever he’s about to endure.

‘‘It’s all about focus, being locked in at all times, because you can’t be messing around on the sidelines, then get your number called,’’ Trubisky said. ‘‘You’ve got to be locked in to the game and try to be step ahead, even when you’re off the field, because there’s some things you can see off the field that you can’t see in the pocket and vice versa.’’

The leap from college football to the NFL is much more challenging than the jump he made from Mentor (Ohio) High School to North Carolina. But Trubisky appears to be ready for the challenge. He might not be ready to win — or even to succeed — but he’s ready learn.

‘‘I don’t think there’s a secret formula,’’ offensive coordinator Dowell Loggains said when asked about the timing of inserting a rookie quarterback. ‘‘Sometimes the best thing is just to get out there and do it. The best way to learn is to make mistakes. Just don’t make the same mistake twice.’’

Follow me on Twitter @MarkPotash.

Email: mpotash@suntimes.com