PHOENIX -- Jarred Kelenic’s introduction to his first Major League camp has already come with plenty of lessons. And the 20-year-old outfielder is passing most of the early tests in impressive fashion, including lacing a run-scoring single and then scoring the winning run in the Mariners’ 2-1 victory over the Brewers on Tuesday in his first Cactus League start.

Seattle’s No. 1 prospect and No. 11 overall went 1-for-3 and broke up a scoreless tie with his base hit in the seventh off Brewers reliever Justin Topa before scoring on Brian O’Keefe’s base hit. He's now reached base in four of his first six spring plate appearances, going 2-for-4 with a double, walk and hit by pitch in his first two games.

Kelenic is destined to open the season in Double-A Arkansas, but he’s making the most of his initial exposure to high-level pitching, and his preparation and knowledge of the game has already impressed his club.

Kelenic watched Topa -- who pitched well out of the bullpen in Double-A last year -- face other hitters ahead of him and jumped on a first-pitch heater to scorch his go-ahead hit.

“I think it was a 98-mph fastball in,” Kelenic said. “Just from what I’d seen, he liked his fastball and threw everything hard. His fastball was hard, his slider was hard, his changeup looked a little hard. So I was just going to ambush the fastball, and luckily, he gave it to me first pitch. I swung as hard as I could, and I think I hit the ball as hard as I could.”

The ability to turn on that pitch is just part of Kelenic’s obvious attributes.

“Plenty of bat speed,” Mariners manager Scott Servais said. “He knows the strike zone so well. He’s got a good swing and is very strong. He has a good idea of what he’s doing at the plate, no doubt.”

That is why the Mariners believe Kelenic could continue moving up the ranks quickly, with the possibility of reaching the Majors sometime in the second half of the 2020 season if all goes well. Servais said Kelenic thinks about the game as well as any young player he’s been around.

“He talks it, constantly," Servais said. "He lives it, he breathes it. Every minute of his life is spent thinking about how he can get better and get the most out of his ability. And it’s rubbing off on a lot of guys around this camp.”

The amazing part is Kelenic was playing high school ball in Wisconsin just two years ago, when he was drafted by the Mets with the sixth overall pick in the 2018 Draft. The Mariners fell in love with him prior to that Draft and jumped at the chance to acquire the promising youngster in the blockbuster deal that sent Robinson Canó and Edwin Díaz to the Mets before the 2019 season.

Having grown up a Brewers fan in Waukesha, Wis., made Tuesday’s game all the sweeter.

“My parents flew in for this game,” he said. “And I have a good relationship with Craig Counsell, the manager over there. It’s pretty cool. I got to talk to him before the game. The Brewers were my team growing up. I live about 20 minutes from the stadium. It’s really cool being out there playing against the Brewers, and hopefully someday I can be out there in a regular-season game.”

Among the biggest lessons Kelenic is picking up is that he needs to relax and enjoy these experiences, despite the self-imposed pressure of trying to live up to the hype of his prospect status and already being a big part of the Mariners’ future plans.

Shortly after Mariners starting pitcher Kendall Graveman talked about regaining his appreciation for the game after sitting out 18 months recovering from Tommy John surgery, Kelenic acknowledged that’s a perspective he’s already trying to remind himself of daily.

“The longer I play professional baseball, the more I realize that baseball is a huge part of my life, but it’s not everything,” he said. “It’s something I’m so blessed [to do] and have dedicated my life to, but going out and spending time with family and friends, that’s what life is about. When I’m inside the lines, I’m going to go out and compete my ever-living you know what off. But at the same time, it’s not everything.

“It’s all about having fun. That’s really what I’m trying to focus on this spring. I’m a very tense individual. So when I say it’s not everything, that’s not me going out and being nonchalant and not caring. Because it’s definitely something I care about. But at the same time, we’re just kids having fun out here.”