While the Titans hunt for a new offensive coordinator, here’s grades of how the team fared in all phases in 2018:

Passing offense: F

The starting quarterback suffered three nerve-related injuries, the team’s top two returning pass-catchers were gone by Week 4 (Delanie Walker suffered an ankle injury and Rishard Matthews was released), and the offensive line was dinged up (and struggled) for a good chunk of the season. So Marcus Mariota and the Titans passing attack had a lot of things working against them in 2018.

Still, ranking 29th in the league with 185.9 passing yards per game is a failure by any measure. Mariota, who failed to start three games due to injury, threw just 11 touchdown passes, the fewest among starting quarterbacks in the AFC South (28 fewer than Andrew Luck, and even a couple fewer than Blake Bortles). While Corey Davis showed glimpses of his potential, it was a mostly disappointing 2018 for the receiving corps, including Taywan Taylor and Tajae Sharpe. The Titans attempted just 40 throws of 20 or more yards, the fewest in the league.

Rushing offense: A-

The Titans’ single-most important development was the emergence of Derrick Henry. It took three-fourths of the season for it to happen, but once it did, the Titans suddenly had a game-changer in their backfield. His 625 rushing yards and eight touchdowns in December led the league by a significant margin.

More:After Titans' Derrick Henry runs all over Jaguars, 'Madden' increases his stiff-arm rating

Before Henry broke out, he flashed encouraging signs during the middle of the season that foreshadowed something bigger (though no one saw a 238-yard rushing performance coming in Week 14). Early in the season, though, Henry struggled as Dion Lewis was utilized as the featured back before that balance did a 180.

Passing defense: B+

The Titans finished sixth with 216.9 passing yards allowed per game, their secondary a strength for most of the season. Among the highlights: cornerback Malcolm Butler turned his season around after a dismal first half of 2018 (seven touchdown passes allowed over the first eight weeks, versus none over the final eight), safety Kenny Vaccaro emerged as a key cog in the middle of the secondary, cornerback Logan Ryan had a stellar 14 games before a broken leg ended his season, and safety Kevin Byard had four more interceptions to give him 12 since the beginning of the 2017 season, which leads the NFL.

The pass rush struggled all season, though and is something that will need to be addressed.

Rushing defense: C+

They stifled Ezekiel Elliott and Leonard Fournette but were run over by Adrian Peterson and Isaiah Crowell. It was hard to predict which version of the Titans’ rushing defense was going to show up, and that inconsistency was one of the key factors working against Tennessee.

The Titans finished 18th in rushing defense at 116.4 yards. Still, the bottom line here (and in passing defense) is the Titans allowed 18.9 points per game, good for third in the league.

Special teams: A-

Aside from punt returns, where Titans returners liked to take fans on nerve-wracking adventures, special teams were a strength.

Brett Kern finished with 16 straight punts inside the 20, en route to his second straight Pro Bowl. The Titans set an NFL record with a 32.0-yard kickoff return average thanks almost entirely to Darius Jennings’ 22 kickoff returns. Jennings’ 31.7-yard average set a franchise record and led the NFL. Ryan Succop missed three extra points over the final five weeks but still hit a solid 86.7 percent of his field goal tries (26 of 30).

More:Titans punter Brett Kern wanted to be a storm chaser. Now it’s helping his NFL career

Coaching: B

Mike Vrabel’s career as an NFL head coach began with the longest game since at least the 1970 NFL/AFL merger, a tone-setter of sorts for what was to come in a wild season. “We didn’t cover that one in the offseason manual,” Vrabel joked. To Vrabel and his staff’s credit, the wackiness of 2018 — which included injuries to key starters, flukey games like that Week 1 marathon at Miami, and a challenging schedule — was handled with about as much deft as fans could hope for from a first-year coach. Yeah, there were a couple of head-scratching moments — handing the ball to tight end Luke Stocker on a fourth-and-inches from the goal line in Week 12 stands out — and no, the Titans didn’t reach their goal of a second straight trip to the postseason. But fans should be encouraged by the overall coaching performance.

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Reach Erik Bacharach at ebacharach@tennessean.com and on Twitter @ErikBacharach.