On Feb. 4, 2019, the Miami Dolphins kicked off their ambitious rebuild by hiring Brian Flores as coach, and 500 days later, on June 18, 2020, the Dolphins are a completely different team.

Gone are many of the Dolphins stalwarts from the past decade, including highly paid veterans who were in the back-half of their careers. Now, there are younger players who have much to prove, many of whom are versatile, fitting the Flores mold. Quarterback Tua Tagovailoa is the prized arrival, but other key cogs of this new era include cornerbacks Byron Jones and Noah Igbinoghene, defensive lineman Christian Wilkins, linebacker Kyle Van Noy and offensive linemen Austin Jackson and Robert Hunt.

The optimism surrounding the Dolphins' future is high, but the team hasn't accomplished anything on the field, yet. Everyone is betting on hope, promise and potential.

That's why the 500-day mark is an interesting milestone to review, and it's a good place to start projecting how the next 500 days will look.

With Oct. 31, 2021 marking the 1,000-day mark of the Flores era, we're curious what the Dolphins will look like and if it will give us more clarity on how effective the rebuild has been. Let's project some realistic examples of best-case, middle-ground and worst-case scenarios for the team on that date.

Best-case scenario

It's the Sunday ahead of a Week 8 prime-time Monday game and Tagovailoa has established himself as one of the NFL's best young quarterbacks with a strong first half to the 2021 season. The 6-1 Dolphins are leading the AFC East coming off a 31-13 thrashing of the New England Patriots in Foxborough, Massachusetts, in Week 7. Tagovailoa leads the NFL in completion percentage and hasn't thrown an interception.

Miami, a trendy preseason pick to make a wild-card push as the AFC East favorite, has quickly become one of the NFL's darling teams. Tagovailoa is the star attraction and hasn't missed a game since taking over for Ryan Fitzpatrick in November 2020. Tagovailoa's immediate chemistry with wide receivers DeVante Parker and Preston Williams have them on pace to be the Dolphins' first 1,000-yard wide receiver duo since Mark Clayton and Mark Duper in 1991.

Despite Tagovailoa's success, the Dolphins' defense is the strength of this team. Xavien Howard and Jones have solidified themselves as the NFL's best cornerback duo, allowing them to scheme pressure and frustrate quarterbacks. Occasional running-game struggles and offensive line inconsistency hold back the offense from being elite, but Flores' defense has held opponents under 21 points in six of their seven games. The Dolphins rank No. 6 on ESPN's Power Rankings, third in the AFC behind 7-0 Kansas City and 6-1 Baltimore.

Fans have rallied behind this Dolphins team more than they have anytime this century.

Middle-ground scenario

The Dolphins' rebuild hasn't been a quick fix, but they continue to head in the right direction. The 4-3 Dolphins are tied for the AFC East lead with the Buffalo Bills and the two square off on this Sunday afternoon in Miami. Tagovailoa is eager to get the Dolphins back on track after a strong September had him in early MVP conversations.

Miami, coming off a 7-9 season in 2020, is ready to make its playoff push in Year 3 of the Flores era. The leaders of this young team have established themselves. Wilkins has received early Pro Bowl love with his team-high 5.5 sacks and seven tackles for loss in seven games. Parker is among the AFC's top-5 receivers. Jackson and Hunt have proved to be solid starting bookend tackles for Tagovailoa.

The second-year QB, who missed two games, has an impressive 68% completion rate, 10 total touchdowns and two interceptions. ESPN's Power Rankings have Miami ranked No. 13, sixth in AFC.

Fans haven't been able to celebrate quite yet, but optimism is high as they wonder if greatness might be realized if we fast forward another 500 days.

Worst-case scenario

Draft fears have come true as Tagovailoa hasn't found a way to shake injuries so far in his young career. He has missed the past five games of the 2021 season because of lower-body injuries, leaving Miami scrambling in what was supposed to be its season to make the playoffs. Instead, the Dolphins are 2-5 headed into a 1 p.m. Sunday game in Buffalo against the 5-2 AFC East-leading Bills. Tagovailoa was a game-time decision, but doctors told him it's a no-go after watching pregame workouts, so it's Josh Rosen who gets another start.

Tagovailoa has created a buzz when he has played, leading Miami to a 2-0 start with four touchdowns and one interception. He hasn't been able to stay healthy, missing 12 of his 20 pro games because of injury. It began when Miami rushed him into the lineup in Week 4 of the 2020 season, which the Dolphins finished 5-11 for the second consecutive year. Tagovailoa hasn't been the only one with injury woes -- Howard's knee issues continued into 2020 and 2021, minimizing the effectiveness of the Dolphins' defense. And Williams hasn't been the same since tearing his ACL in 2019.

There's still some optimism the Dolphins can turn it around because Tagovailoa has looked good when healthy and the Dolphins have lost a lot of close games. But TV talking heads are not criticizing the Dolphins' decision to draft Tagovailoa at No. 5 overall in 2020. ESPN's Power Rankings have Miami at No. 26.

The fan base's pessimism has started to sink in. The prevailing thought is, "Man, what a rough last 500 days it has been."