The Pittsburgh Steelers ended the season with a 36-17 loss to the New England Patriots. Here is a look at the season and what's next:

Season grade: B+

Season summary: An ugly loss to the Patriots will give the Steelers a bitter taste all offseason. But a nine-game winning streak to spark a division title and a mini-playoff run was a brilliant turnaround from a 4-5 start. The defense played inspired football, averaging 16.5 points allowed per game during that winning turn. First-round picks Ryan Shazier, Bud Dupree and Artie Burns were starting to produce at high levels. Ben Roethlisberger was one of the league's least-sacked quarterbacks, validating the $100 million-plus long-term investment in the offensive line. Le'Veon Bell was arguably the league's best all-around player in the season's second half. Roethlisberger's fourth-quarter performance against the Baltimore Ravens in Week 16 was one for the ages. Antonio Brown was among the league leaders with 12 touchdowns and another 100-catch season. The only complaint is the Steelers shouldn’t have needed such a valiant, late-season effort. An ugly, four-game losing streak exposed a defense that blew assignments, and those demons returned for Sunday's loss. Big Ben called out teammates for lack of accountability. Yes, Dallas and New England were on the schedule during that stretch, and credit the Steelers for rallying from that dark time. A B+ grade seems about right for a team that entered the year as a trendy Super Bowl pick. But things could have been smoother. In the end, losing home-field advantage for the final two playoff games hurt, although location may not have mattered Sunday, especially after Bell injured his groin in the first quarter and had just one carry on the ensuing series before being shut down for the remainder of the game.

Biggest draft need: Wide receiver/tight end. What was once a position of strength now needs a reliable second pass-catching option alongside Brown. Martavis Bryant will be back but must regain trust after back-to-back drug suspensions. Sammie Coates struggled through injuries in Year 2. Eli Rogers has progressed well but is considered a complementary piece for now. Markus Wheaton, a free agent in 2017, spent most of the season on the sidelines with injuries. Offensive coordinator Todd Haley, with his wide receiver background, would love to develop a top-shelf playmaker as a vertical threat. Tight end could be a position of need if Ladarius Green continues to struggle with injuries and concussions. But otherwise, the Steelers are mostly in a good spot depth-wise. The recent defensive draft picks are panning out, leaving the Steelers secure at defensive line, inside linebacker and the defensive backfield. Alejandro Villanueva and Jerald Hawkins are the future at left tackle. Perhaps another outside linebacker is in play to replace soon-to-be free agent Jarvis Jones, who fell out of the rotation this season. But Big Ben needs more weapons.

Key offseason questions:

Can the Steelers keep their offense intact? Bell's free agency will test the Steelers' financial commitment to the running back position, but Bell isn't the only question looming for the Steelers, who figure to have more cap space than in years past. Brown enters the final year of his contract, and after reworking his deal in back-to-back years, the 28-year-old won't want to play for $4.71 million in 2017. Free agent Villanueva is worth an investment. On defense, end Stephon Tuitt enters the last year of his deal. The Steelers like to reward good, young players with new deals entering their final seasons, and Tuitt could be next. Veteran Lawrence Timmons, also a 2017 free agent, has been resurgent in his 10th season, showing the ability to cover tight ends downfield and stop the run. The Steelers must spend wisely to keep key pieces in Pittsburgh.

What pieces can the Steelers add on defense to go from good to great? The Steelers' defense is in a good place but can still make a sizable jump. Who will bolster the pass rush, which runs hot and cold? Perhaps a draft pick will. The Steelers had one of the league's lowest sack totals through the first half of the season before exploding with 18 sacks over a five-game stretch. With or without the 38-year-old James Harrison, the Steelers could use a building block at outside linebacker alongside Dupree, whose athleticism is obvious but needs refinement bending the edge. Vince Williams can slide into the inside linebacker spot alongside Shazier if Timmons doesn't return. The secondary is in good shape, assuming Burns and safety Sean Davis continue to develop and oft-injured draft pick Senquez Golson returns. One more piece on the interior defensive line with Javon Hargrave will provide much-needed depth.

What will shore up special teams? This isn’t an attractive storyline, but it's crucial for the Steelers, who offset good coverage moments with a few costly lapses and kickoff errors by Boswell. A blown coverage in Baltimore in Week 9 got Jordan Berry's punt blocked and probably cost the Steelers a cleaner path to a division title. Boswell's muffed onside kick in Baltimore in Week 9 and two out-of-bounds kickoffs against the Ravens seven weeks later were curious moments since he's so reliable with field goals. With special-teams dynamos Darrius Heyward-Bey and Shamarko Thomas missing significant time with injury, the Steelers need to identify eager playmakers in this area. Pittsburgh ranked outside the NFL's top 15 in most special-teams coverage categories.