PEORIA, Ariz. — Felix Hernandez seemed perplexed when he saw the small group of writers waiting to corner him at his locker in the Mariners’ spring training clubhouse on Tuesday afternoon — report day for the team’s pitchers and catchers.

“Already?!?!” he said.

Yes, Felix. Already.

Regardless of his casual surprise — real or feigned — there is no bigger story going into the Mariners’ 2017 season than their longtime ace and his battle against Father Time and a mounting number of innings piled on his right arm.

For the Mariners to finish over .500 for a second straight year, and more important earn the club’s first postseason appearance since 2001, the 31-year-old Hernandez must return to some semblance of his former self.

Can he do that?

“I’ve got to prove people wrong,” he said. “I feel fine. I’m healthy and that’s the main thing.”

And yet there are a fair amount of people who are skeptical, given his age, the innings accrued, his meandering command and decreased velocity.

Does he think people are beginning to doubt him?

“Sometimes, I think so,” he said. “I don’t know why. I’m still here.”

Much of that could stem from last season, where he posted an 11-8 record with a 3.82 ERA in 25 starts, while spending almost seven weeks on the disabled list with a calf injury. While he wasn’t his former Cy Young self, and there is fair reason to wonder if he’ll ever be that guy again, Hernandez was almost good enough to lead the Mariners to baseball after Game No. 162. If he could have avoided the disabled list, or worked through some of his mechanical and command struggles during his other starts, the Mariners’ 86-76 record might have improved by a game or two, giving him his first appearance in the postseason.

On the final day of last season, his manager and general manager publicly encouraged/challenged Hernandez to put more work in during the offseason and become more focused in his preparation. It was something that hadn’t been levied at him in his time with the Mariners.

Hernandez flushed the disappointing results of 2016 when the season ended, choosing not to relive or reflect on what he couldn’t change.

“I wasn’t thinking about anything,” he said. “I just wanted to forget about everything and have fun in the offseason.”

That fun included a trip to Africa and a safari with his family and then some quality time spent with Iron Glenn.

Iron who?

That would be Iron Glenn Freeman.

The New York-based trainer, who works with Robinson Cano, Nelson Cruz, Yankees reliever Dellin Betances and more, helps athletes have “fun” working out and preparing for the upcoming season.

“I talked to Cano and Nelly about him,” Hernandez said. “I went to New York to see him and I worked out with him for four days there and then we decided to keep working out in the offseason.”

The videos began to pop up on Instagram and Twitter with a slew of hashtags like #ReturnOfTheKing. They showed Hernandez doing an assortment of highly intense workouts featuring medicine balls, elastic bands and other apparatus. This wasn’t 30 minutes on an elliptical trainer and some sit-ups.

“It was hard,” he said. “Those bands were hard. It was tough workouts. I was working on everything. It was the whole body. I needed to be balanced — left and right side. We did a lot of bands.”

It was slightly more technical than “working on everything.”

“My philosophy is different when it comes to training,” Freeman said. “It’s not about beating up a player, especially baseball players because their movements are all about consistency — consistent arm slot, consistent swings. So you must facilitate moves in training that will allow them to do that. You must allow their muscles to communicate constantly.”

Freeman could see there was little communication from Hernandez’s muscles.

“I look for flaws in a person’s kinetic chain,” he said. “Let’s say if you stand on one leg and you are unstable from the ankle, the body instantly will start shutting off power in increments as it communicates to the arm. The goal was to remove the instability from his ankle. We are trying to get his velocity back to 93-94, that’s the goal. So allowing us to remove the flaws from his kinetic chain will do that. He had that calf issue and that did not help his power either.”

It wasn’t a perfect marriage to start.

“When I say he worked hard, he worked hard,” Freeman said. “The first day was sketchy, the second day was sketchy. But once he understood what we were doing, he instantly bought into it.”

It helped that Freeman could show him how the moves in the gym would affect his actions on the baseball field.

“It’s easily transferable,” he said. “He was able to start throwing the next day and he could feel the difference of how his body reacts because now his legs are communicating with his arm.”

Hernandez trained with Freeman before and after his two starts in the Venezuelan Winter League. The sessions lasted up until a week ago. By appearance, there is a noticeable gain in muscle and size on his frame.

“I weigh 224 right now,” he said. “I was too skinny last year, I was about 207.”

That added muscle was earned with Freeman.

“He kills you in the weight room, but it’s fun,” he said. “Those two hours are fun for him and they are fun for us. I feel different. I feel really good.”

Besides the strength work, Hernandez started his throwing program earlier in preparation for pitching in the World Baseball Classic. After being forced to miss the WBC in 2009 while signing a contract extension, Hernandez is anxious to represent Venezuela.

“It means a lot to me,” he said. “I think we got a pretty good team to win the whole thing.”

Hernandez will be on a different throwing schedule than in year’s past where he didn’t step on the mound until about 8-10 days into spring. He’ll work with pitching coach Mel Stottlemyre to get that figured out.

“I don’t know,” he said. “I gotta talk to Mel. I think I’m going to start throwing bullpens in two days, three days. I have to get ready to pitch before Puerto Rico.”

That start against Puerto Rico will open WBC Pool Play in Jalisco, Mexico on March 10. Hernandez expects to make two Cactus League starts and pitch a total of four innings before that.

While it’s admittedly chaotic and worrisome to have his No. 1 pitcher leave for the WBC, Stottlemyre was ecstatic about Hernandez work in the offseason. He watched the videos, talked with Hernandez often and can see the changes.

“I loved it,” Stottlemyre said. “He looks different. That’s all I can say. Knowing what he went through last year, he looks different in a good way. He seems a little more focused. He has a little more of a plan coming into this spring. I’m not going to say he’s taking things more serious, but I would say there is a more defined plan in to what we want to do. He’s on a mission. He needs to be. He’s still our guy.”