The Miami Dolphins ended the season a with a 42-17 loss to the Buffalo Bills to finish the season at 7-9. Here's a recap of the season and what's next:

Season grade: Average -- Most preseason projections had the Dolphins lucky to get to 7-9 or 8-8, so it’s hard to say they fell below expectations. But there has to be a lingering frustration for Dolphins owner Stephen Ross and fans that their team remains cloaked in mediocrity. An improvement over their 6-10 record in 2017 is noteworthy and coaches will likely use that as a sign of progress particularly due to their injury burden. But as the Dolphins head into 2019, it’s hard to say we know more about the long-term future than we did six months ago. That makes it somewhat of a lost season.

Season in review: The Dolphins had one of the NFL’s worst statistical offenses and defenses, but they were in the playoff hunt until Week 16 because they were 7-1 in games decided by eight points or fewer up until that point. Miami started off as one of the NFL’s biggest surprises jumping out to a 3-0 record thanks to explosive plays and a ball-hawking defense. Quarterback Ryan Tannehill played well, too, in his first action since December 2016. But back-to-back losses followed and Tannehill’s shoulder capsule injury put a damper on the second quarter of the season. Tannehill missed five games -- backup Brock Osweiler started with a win over Chicago and ended with no offensive touchdowns over his last nine quarters -- and the Dolphins went 2-3. Injuries to key offensive players helped turn what had become an exciting, big-play offense to a relatively ineffective and occasional big-play offense. The Miami Miracle -- a 69-yard hook-and-lateral Kenyan Drake TD to beat the Patriots in exciting fashion -- was the highlight of the season. But the Dolphins were doomed by their inability to win on the road. The offense was flat-out bad much of December as the offensive line crumbled and Tannehill couldn’t do anything special to save them.

He said it: “It’s not good football if you are going to be inconsistent ... It’s not complementary. It doesn’t work.” -- Dolphins defensive end Cam Wake

Offseason questions

What is the Dolphins long-term answer at QB? This remains the Dolphins biggest question mark for the second consecutive season. Tannehill is a legitimate starting quarterback who can keep Miami in the playoff picture annually, but is he good enough to take them to the next level? Miami has spent seven years waiting to get a definitive answer and it might decide time is up. Coach Adam Gase is a huge Tannehill supporter, and if the coach returns, he might want to bring Tannehill back. Tannehill is also due an $18.7 million salary in 2019 to go along with his $26.6 million cap hit. But QB competition is sparse in Miami, and no, Osweiler, doesn’t scare anyone. Free agency and the draft market don’t appear strong this offseason, but Ross will likely want his decision-makers to address the QB position regardless. Is this the year the Dolphins draft their first quarterback before the seventh round since 2012? It should be -- specifically in the first three rounds -- whether Tannehill returns or not.

Which personnel direction do Dolphins choose to follow more: veteran culture or youthful promise? Gase wanted to build a 2018 Dolphins roster that could overcome adversity, so he brought in veterans such as Frank Gore, Danny Amendola, Josh Sitton, Daniel Kilgore and Akeem Spence. The results were up and down, but three of those players ended the season on injured reserve. There will be a decision due on longtime Dolphins veteran Cameron Wake, who will be a free agent. Also, Miami will have to decide whether to clear paths for promising young players such as Minkah Fitzpatrick, Kenyan Drake and Kalen Ballage -- each of whom was somewhat blocked by veterans. Xavien Howard, Laremy Tunsil and Fitzpatrick are recently drafted players to build around, but are they ready to be leaders? There is a talent void and the Dolphins will have to decide whether fix it with youth or veterans.

How will Miami rebuild its defensive line? Miami’s defensive line is the position group most in need of an overhaul. The Dolphins rank in the bottom five of the NFL in sacks, and they sport one of the NFL’s worst run defenses. On the edge, Robert Quinn and Andre Branch are due huge salaries and could be candidates to be cut. Charles Harris, a 2017 first-round pick, has been a disappointment with just three sacks in his two NFL seasons. Wake is a free agent. Miami needs to add at least two and possibly more edge rushers to this group -- and it’s likely the team’s biggest need. Defensive tackle is an issue as well. The Dolphins never properly replaced Ndamukong Suh. William Hayes and Vincent Taylor, arguably the Dolphins most productive run-stuffers, were both on injured reserve by midseason and they will have to utilize the draft or free agency to fill that hole.