PHOENIX, Ariz. – Marcus Mariota’s 2018 injury list was even worse than we thought, I’ve learned.

The ulnar nerve issue in his throwing arm that started when he got stepped on opening day in Miami and left him with a tingly hand was the first big one. He missed two starts with that, though he played in the second one.

The neck stinger suffered in Indianapolis on Nov. 18 and then reaggravated in Week 16 in Washington that cost him the crucial Week 17 game against the Colts was the second.

He also suffered a cracked vertebra, presumably with the initial stinger. [Unlocked]

There was a significant tear of the plantar fascia in a foot that finally tore all the way in Week 16. That is actually often regarded as a good development that relieves the severe pain, renders surgery unnecessary and allows a player to learn how to play without the support of the ligaments.

He also dealt with a strained oblique, a broken rib and a sprained AC shoulder joint along the way.

Mariota missed three starts and didn’t finish three games due to in-game injuries.

He was on the injury report with the right elbow suffered in the Week 1 loss in Miami for Week’s 2-5 and missed starts versus Houston and at Jacksonville, though he quickly entered the game against the Jaguars when Blaine Gabbert suffered a concussion.

Mariota was on the Week 13 and Week 15 injury reports with “abdomen,” the Week 14 report with “right hand,” and the Week 17 report with “neck/foot.”

Teams are only obligated to report injuries that impact a player's ability to practice or play.

Learning more about the injuries may help explain a bit about Mariota’s struggles last season, when he threw only 11 touchdown passes with eight interceptions. His completion percentage was a career-best .689 but he also took a career-high 42 sacks.

He unquestionably needs better weapons and better protection, and the Titans got to work on that right away in free agency by adding slot receiver Adam Humphries and left guard Rodger Saffold.

But while there is a great degree of bad luck in the injuries he suffered last year and in the three prior years of his career, quarterback injury avoidance is also somewhat of a skill, one he needs to get far better at in the most crucial year of his football career.

(Here is a story I did in 2014 at ESPN.com: Is there a skill to staying healthy as a QB?)