Well, here we go again: Writing once more why Ryan Tannehill is the key to another Dolphins season. What is this, six, seven times now? It’s become awkward to write this column about Tannehill, year after year, because every year really looks like his year to prove himself.

Every year something gets in the way, too. Bullygate wrecked one year. Coach Joe Philbin’s belated firing did another. There was the knee injury just as Tannehill had found his good stride with current coach Adam Gase in 2016, and then the re-injury last August that cost him a full season.

So this is the year.

Funny thing is, I believe it, too. Any issue holding back Tannehill is gone. It’s all on him now. Gase, unlike Philbin, is completely behind Tannehill to the point their careers are happily tied together. The Dolphins even passed on drafting one of the top quarterbacks available because they believed in Tannehill.

For another, there’s Tannehill’s time off. The knee has healed to the degree he says, “At this point, it’s like nothing ever happened.” There’s also the idea that, in retrospect, this 20-game breather can be re-scripted in a positive way.

“I’ve grown a lot as a leader,” Tannehill said. “I’ve grown a lot as a person, a football player, just because of the adversity I’ve faced. Being able to take a step back and watch from a different perspective and take in that information, file it away, write it down.

“I’ve been going back looking at my notes of things that hit me over the last 16 months, whatever it may be. I’ve just built on that. It’s an experience that, while I’d never want it to happen that way, has been invaluable to me.”

Finally, the last reason to believe this is finally his prove-it year is this is completely his team now. You couldn’t say that previously, as we know now Alpha males like Jarvis Landry and Mike Pouncey weren’t fully on board with Tannehill. But now look around this offense.

He’s the old guy now.

He turns 30 on Friday.

“I don’t feel old,” he said. “I feel great. I don’t feel like I’m about to be 30. But I am one of the old guys. I’ve played a lot of football here in Miami. It’s kind of a fun transition in the past here years, transitioning from one of the young guys to one of the more veteran guys.”

As if to underline that idea, Tannehill played with his 2-year-old son on the field after practice Thursday while talking with his pregnant wife. He’s not just grown up by now. He’s grown a family. He’s grown old, at least by the way sports keeps score.

The season rests on him, of course. Gase says that’s not the case. He says this team can win. But we saw what happened last year when he was lost. It wasn’t pretty, just as it usually isn’t across the league. Look at Houston when DeShaun Watson went down, Green Bay when Aaron Rodgers went down, Arizona when Carson Palmer went down.

Of course, Minnesota did great without Sam Bradford, and Philadelphia won the Super Bowl without Carson Wentz. The Dolphins aren’t those teams. Their roster isn’t that strong. Their back-up, too, is untested David Fales.

There is something being made of him wearing a knee brace saying, “Ryan Tannehill 2.0,” as if it’s a new and improved version of him out this year. He also put out a video in social media showing him working out with receivers this offseason, perhaps a jab at Landry saying Tannehill wouldn’t work out with him.

No quarterback is tougher. No Dolphin works harder. No one has a simpler approach to his craft, as Tannehill again showed when asked what he wants for his 30th birthday.

“Great day of practice,” he said.

That’s Tannehill. You root for people like him in life. But rooting for him doesn’t change the conclusion: This is his year to prove himself. Either he makes it or doesn’t. But this is the last time this kind of column gets written to start a training camp.