Why Mitch Trubisky's preseason dominance might mean nothing

Riddick: Bears should temper excitement for Trubisky (1:54)

Louis Riddick breaks down why WR Cameron Meredith's injury could keep Mitchell Trubisky as Mike Glennon's backup QB. (1:54)

Mitch Trubisky is That Guy for the 2017 preseason. You know, the one whose performance in exhibition games -- often against opponents' second- and third-team players -- generates buzz and gets everyone all excited about what might be in store sooner rather than later.

Trubisky, the No. 2 overall pick of this spring's draft, mounted an unexpected challenge to the Chicago Bears' starting quarterback spot. He completed 36 of 53 passes for 364 yards and three touchdowns without an interception, the most interesting development of what is usually a dull portion of the NFL calendar.

And for what it's worth, Trubisky will join a list of players who spawned a similar preseason story. How did it work out for Those Guys? Let's take a look back over the past five years.

2016: QB Dak Prescott, Dallas Cowboys

Preseason: After entering the preseason competing for the Cowboys' No. 2 job, Prescott finished it as their starter after Tony Romo's back injury. Even before Romo was injured, however, Prescott had impressed the NFL world with his accuracy and composure in the pocket. He wound up leading the NFL preseason with 151 yards per game and five touchdown passes, and ranked second with a 137.8 passer rating.

What happened next: How could we forget? Prescott led the Cowboys to a 13-3 record and the No. 1 seed in the NFC playoffs. He ranked third in Total Quarterback Rating (81.5), was named to the Pro Bowl and won NFL Offensive Rookie of the Year honors. In their long-range planning, the Cowboys had envisioned Romo as their quarterback for several more years. Prescott changed all of that.

2015: RB Jarryd Hayne, San Francisco 49ers

Preseason: Remember the Australian rugby star who took the NFL by storm? After signing with the 49ers at age 27, Hayne finished second in the preseason in rushing yards (175) and yards per carry (7.0). He also made some big plays, ripping off a 27-yard punt return, a 33-yard kickoff return and 34-yard rush.

What happened next: Hayne improbably made the 49ers' 53-man roster as a return specialist, but he never replicated the preseason excitement. He dropped his first career punt-return attempt, in Week 1 on Monday Night Football, and averaged 9.5 yards on eight returns before the 49ers waived him and placed him on their practice squad. Hayne returned to rugby the following spring. Oh, what might have been ...

2014: QB Blake Bortles, Jacksonville Jaguars

Preseason: The prevailing wisdom at the time was that Bortles, the No. 3 overall pick of the draft, would need a year or more of development before he was ready to play. The Jaguars planned to start veteran Chad Henne for as long as they needed to. Bortles, however, capitalized on low expectations to produce a better-than-anticipated preseason. He completed 62.7 percent of his passes for an average of 10.2 yards per attempt, fifth in the NFL.

What happened next: The Jaguars felt they had no choice but to start him. Alas, Bortles has never played as well as he did in his first preseason. He has completed 58 percent of his passes in each of his three regular seasons as the Jaguars' starter. Bortles has averaged 6.6 yards per attempt, and he has thrown the second-most interceptions (51) over that time period. The Jaguars wanted to bench him after a miserable 2017 preseason, but Henne was no better.

2013: TE Ladarius Green, San Diego Chargers

Preseason: After catching four passes in four games during his rookie season, Green took what appeared to be a huge leap the following preseason. He finished third in the NFL with 210 receiving yards. Of his 13 receptions, nine went for first downs. Five gained at least 20 yards. As starter Antonio Gates hit his 33rd birthday, it appeared the Chargers had a genuine heir on their hands.

What happened next: Green improved his production but never came close to matching his preseason promise. He scored seven touchdowns over the next three seasons before signing with the Pittsburgh Steelers in 2016. He was cut in May after playing in only six games and is currently unsigned. Gates? At 37, he's still the Chargers' starter.

2012: QB Kirk Cousins, Washington Redskins

Preseason: When the preseason began, Redskins fans were curious more than anything else about why their team drafted Cousins in the fourth round after trading up to select Robert Griffin III in the first round. They got their answer with Cousins' preseason performance. He led the NFL with 560 yards, accounting for 30 first downs, the second-highest total in the league. No one questioned Griffin's credibility as the starter, at least not then, but the seeds of the eventual Griffin-Cousins competition had been planted.

What happened next: Cousins opened eyes in relief of Griffin during the next three seasons, even though he committed a turnover once every 29 snaps, worst in the NFL. But when Griffin suffered a concussion in the 2015 preseason, Cousins was the natural replacement. He remains the starter and has been the Redskins' franchise player the past two seasons. In this case, the preseason hype proved valid -- eventually.