Kansas City Chiefs at crossroad entering 2018

KANSAS CITY, Mo. -- A season that started with Super Bowl aspirations for the Kansas City Chiefs and included a red-hot 5-0 start that kicked off with an upset win over the defending Super Bowl champion New England Patriots turned south at midseason, with the fallout leaving the franchise at a crossroad heading toward 2018.

The Chiefs' bewildering season ended with a frustrating 22-21 loss to the Tennessee Titans in the wild-card round. The game served as a metaphor of sorts for the team's season, with a second-half letdown fueled by a leaky defense allowing a big lead surrender and the Chiefs unable to rally at the end.

Yet the collapse leaves head coach Andy Reid with a hint of optimism looking toward next season. He values the grit his team showed in shaking off a 1-6 slump and rallying for four-straight wins to claim back-to-back AFC West titles for the first time in franchise history.

"A lot of times when things go south they go south fast and never recover," Reid said. "It's happened to a lot of football teams. This group here rallied back through whatever injuries you want to look at and adversity and put together a pretty good season."

The Chiefs' transition quickly with a new offensive coordinator and a shuffling in the team's scouting department. More changes are likely as the team ponders difficult roster decisions, including one between veteran Alex Smith or youngster Patrick Mahomes at quarterback next season.

WHAT WENT RIGHT: The offense shined in 2017 with quarterback Alex Smith turning in the best season of his career with 4,042 yards passing and 26 touchdowns. Tight end Travis Kelce turned in another 1,000-yard season, Tyreek Hill blossomed into a No. 1 wide receiver with a 1,000-yard season of his own and the Chiefs found their heir apparent to running back Jamaal Charles in rookie Kareem Hunt.

WHAT WENT WRONG: Kansas City's defense never found its footing, ranking in the bottom quarter of the league against both the run and the pass and struggling in key situations including third downs and in the red zone. The defense showed a disappointing tendency to let down late in games, surrendering second-half leads four times including in the disappointing playoff loss to the Tennessee Titans.

MOST DISAPPOINTING PLAYER: Wide receiver De'Anthony Thomas. The Chiefs hoped that Thomas might finally find his role in the team's passing game in his transition to wide receiver, but the fourth-year player turned in another below-expectations season. Thomas caught just 14 passes for 143 yards and lost his job as the team's top kickoff returner. Thomas unfortunately suffered a serious leg injury in the regular-season finale, undergoing surgery for a broken leg. With Thomas wrapping up the final year of his rookie contract, this looks like the end of the road for his time in Kansas City.

MOST SURPRISING PLAYERS: Running back Kareem Hunt. The club thought they found a diamond in the rough with their third-round selection from Toledo, but no one expected so much so soon from Hunt. The rookie found himself thrust into the starting role after incumbent back Spencer Ware went down for the season with a knee injury in the preseason. Hunt responded by winning an NFL rushing title and setting a league record by topping 100 yards from scrimmage in each of his first seven games as a pro.

Wide receiver Albert Wilson. The fourth-year receiver set career highs with 42 catches for 554 yards and three touchdowns in just 13 games. His value in Kansas City's offense goes beyond the role of pass-catcher, however, with the gritty 5-foot-9 Wilson using his speed in the team's motion and jet sweep packages and bringing a fiery attitude to the field.

ASSISTANT COACH ON THE RISE: With Matt Nagy already moving on as head coach of the Chicago Bears and Eric Bieniemy earning a promotion to offensive coordinator, keep an eye on newcomer Mike Kafka. The 30-year-old retired quarterback held the position of offensive quality control coach, but his primary responsibility centered on helping rookie Patrick Mahomes make the transition to the NFL. Kafka remains a candidate as the team's next quarterback coach, and with Reid's staff serving as a cradle for offensive coordinators and head coaches, Kafka appears in line as the next generation.