When this season began, there was certainly optimism for the Miami Dolphins. Miami brought in Mike McDaniel, the former offensive coordinator with the San Francisco 49ers, to be head coach. They made the bold move in the offseason to trade for All-Pro wide receiver Tyreek Hill. They already had a stud rookie receiver in Jaylen Waddle. They even signed a couple of talented running backs in Raheem Mostert and Chase Edmonds.

However, after Dolphins quarterback Tua Tagovailoa suffered a serious concussion, it appeared the season was turned upside down. The Dolphins went from 3-0 to 3-3 what felt like overnight. Much of the positive vibes were fading. But since they got Tagovailoa back last week, people are being forced to remember how dangerous this team can be.

On Sunday, the Dolphins once again showcased their offensive talent in a comeback 31-27 victory on the road against the Detroit Lions Sunday. They improved to 5-3 on the season with a favorable schedule coming up.

Considering all of that, the Dolphins would be wise to look to add pieces. Here are the three reasons why the Dolphins should be buyers at the NFL trade deadline.

3. Dolphins Wide Receiver Duo Cannot Be Covered

Entering Week 8, the Dolphins had the NFL's leading receiver in Tyreek Hill. Hill had 773 receiving yards. His teammate, Jaylen Waddle, was fourth in the NFL with 621 yards. Once again, both of them completely dominated on Sunday. Hill led all receivers across the league with 188 more yards, bringing his season total to 961 yards. Keep in mind, we have only played just under half the season.

Not to be outdone, Waddle added 106 more to his total with two touchdowns.

We have not seen a wide receiver duo this productive possibly ever. They are on pace for over 1,900 and over 1,600 yards respectively. That is flat out ridiculous. A lot of people thought that Hill's numbers would come down to Earth going to Miami. Instead, he is having the best season of his career.

Anytime you have Hill and Waddle on the field, you can score on any play. This offense is legit and it's not going anywhere.

2. Miami defense is better than it has shown thus far this season

The last couple of seasons, the Dolphins defense has been by far the better unit. They finished top 10 in almost every statistical category last year, and shut down some of the NFL's best offenses. Yet, this year they have really struggled.

They allowed 38 points to the Baltimore Ravens, 40 points to the New York Jets and then 27 in the first half to the Lions Sunday. But they must have figured something out as they shut out the Lions in the second half, allowing for the comeback win.

The Dolphins have an elite cornerback in Xavien Howard. But the other side has been an issue. Nik Needham was already struggled and was recently placed on injured reserve. Byron Jones has been out for a month and it's not yet known when he will return. Noah Igbinoghene started at right cornerback and has struggled in coverage. It is pretty clear that the Dolphins secondary has been the biggest weakness of the team.

Both the Carolina Panthers or Houston Texans have some really good players in their secondary. Both teams are likely to be sellers at the trade deadline. A Dolphins trade with either of them would make a lot of sense.

1. Dolphins are a playoff team

After play Sunday, the Miami Dolphins are right in the thick of the playoff race. They are currently the sixth seed in the AFC. Even though it is unlikely that they catch the Buffalo Bills in the AFC East, they have a very good chance at making the playoffs even if they don't make any trades.

It's worth mentioning they do currently own the tie-breaker over the Bills after beating them in Week 3.

Miami also owns the tie-breaker over fellow wild card contender, the Baltimore Ravens, via their Week 2 insane comeback win.

Over the next three weeks, the Dolphins will play the Chicago Bears, Cleveland Browns and Houston Texans. They were be easily favored in each of those games. There are some tough games for the next few weeks but Miami then closes with a couple divisional games against the New England Patriots and New York Jets.

We can't forget that this team looked like one of the best in the NFL until Tagovailoa was injured. The Dolphins have won 12 of their last 13 games that Tagovailoa started and finished. Most people like to disrespect him, but at this point, it's fair to say that he is a winner, at the very least.

He has a 19-9 career record as a starting quarterback. There is plenty of reason for Miami to be optimistic and go make a trade at the deadline.