SURPRISE, Ariz. -- The hand-written notebook that Jarred Kelenic arrived to Spring Training with will have another detailed entry after he emphatically crushed two homers on Sunday, turning in what’s easily been the Mariners’ most impressive individual performance of this young Cactus League season.

The big blasts in Seattle’s 8-7 loss to Kansas City were almost copies of each other -- both no-doubters off the bat, both in 2-1 counts and both way beyond the center-field wall, just narrowly to the pull side. The first went 428 feet with a 113 mph exit velocity and the second traveled 438 feet at 107 mph. Kelenic also ripped a 328-foot lineout to center in his final at-bat, also at 107 mph.

“I'll write down that I won every pitch today,” Kelenic said of the mementos he began tracking after an extensive offseason training with coaches in Southern California. “I didn't really chase. I had a plan coming into the game today, and I executed every single pitch. It's just one of those days. It's not going to be like that every day, but it was definitely a day where I had a plan, and every single pitch, I won.”

The metrics were provided by TrackMan at Surprise Stadium and not Statcast, officially. For context, only Aaron Judge, Yordan Alvarez, Joc Pederson and Oneil Cruz had more than three batted balls at 107 mph or harder in a single regular-season game last year. For the Mariners, only Nelson Cruz -- just once -- has had more than three in a single game since Statcast came online in 2015.

“[Kelenic] has kind of revamped his swing a little bit. You are going to see more balls in the middle of the field and to the opposite field,” Mariners manager Scott Servais said. “But I'm really happy where he's at. The timing is there. He's right on everything. There are still going to be some bumps in the road along the way, but it doesn't get much better than what he did today.”

Beyond the metrics, the more telling takeaway for Kelenic was how he made such punishing contact -- from his new setup in the box to leveraging counts to successfully staying in the middle of the field.

After toying with multiple stances in his first two seasons, Kelenic’s latest looks mostly identical to the one he finished with last year, other than the addition of a minor elbow twitch just ahead of the pitcher’s windup. More subtly, he’s also moving his back (left) knee. Both additions aim to create a better rhythm since he’s admittedly stationary in the box.

“He's been in a great frame of mind and believing in the adjustments he has made over the winter,” Servais said. “It's great when you get some results early on. ... There’s no question, he looks more comfortable.”

Kelenic’s homers were in hitters’ counts and the lineout was after he fell behind, 1-2. One of the Mariners’ pointed instructions for him when they sent him to the Minors for more than two months last summer centered on a two-strike approach. Over his first two seasons, Kelenic hit .183/.413/.450 (.863 OPS) when ahead in the count and .156/.160/.271 (.431 OPS) when behind. But he’s taking a more grounded approach this spring.

“I'm trying to have a mindset that it doesn't matter what the count is,” Kelenic said. “I'm just trying to, seriously, take it one pitch at a time and then trying to flush the rest. It's helping me with situations like that, so that the thought of having two strikes doesn't become overwhelming.”

It’s been well-chronicled that this could be a decisive season for Kelenic. He has the safety net of a platoon with veteran AJ Pollock that could provide him the runway to succeed, especially early, but he also has just one Minor League option left. It was only two years ago that he was MLB Pipeline’s No. 4 overall prospect and had all the tools and potential to back it up.

Those are still there -- as is his relentless drive to continue learning and adjusting.

“It's kind of just been my approach throughout the whole offseason,” Kelenic said. “Just trying to stay inside every pitch and, again, trying to win every pitch. I feel great. I'm in a great spot. It's day two, but tomorrow I'll be in there again and we'll be able to strap up. I’ll enjoy this because it was a good day, but then I'll strap it on tomorrow and try to do it again.”