The world is full of dynamic duos. Music has McCartney and Lennon, Jagger and Richards, and about a million others. Acting has Newman and Redford, Pacino and De Niro, Sandler and Barrymore. Basketball fans can point to Stockton and Malone or the Splash Brothers in Golden State. We could go on forever.

Baseball certainly has its own. Canseco and McGwire. Maddux and Glavine. Mantle and Maris.

I don’t know that we’ll need to speak of the Mariners’ Julio Rodríguez and Jarred Kelenic in quite those same reverential tones, but in order for this rebuild to work, they’ll need to be good. Very good. Maybe great. And no one will complain if they reach the ultimate level.

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This spring has been all about Julio. He has torn the cover off the ball, dazzled with his smile, impressed with his command of the language, improved his speed (which he used to dash around the bases for an inside-the-park home run Thursday night) and capably manned center field. If he doesn’t start in center on opening day for the Mariners, let alone make the team, there may be a riot at the corner of Edgar and Dave.

And while Julio’s Rookie of the Year campaign seems all but a fait accompli (kidding – kind of), nothing would be more important to the Mariners’ success this season than for Kelenic to live up to the lofty hype that has surrounded him since the day he arrived in the trade that sent Robinson Canó and Edwin Díaz to New York. Heck, if he can just avoid the dry spells like he had last May and look more like the player he was in September, everyone should breathe a little easier.

Especially him.

There is no doubting Kelenic’s talent. He is made of muscle, his swing is smooth and powerful, and he has hit at every level. And he showed us last year that when hot, he can carry a team – even as a 22-year-old rookie.

The questions about Kelenic are about his mind. Not his understanding of baseball – he sees the game well. No, it’s his emotions, and specifically his ability to control them. It was clearly a challenge for him when he was first called up last May. We heard stories of broken bats and bashed helmets in the tunnel. He was struggling to live up to his trademark confidence/cockiness, and when he couldn’t, it spiraled on him.

When he was eventually sent back down to Triple-A Tacoma, it was brutal.

“Being sent down is super hard on your mental health,” he told me this spring. “It makes you question a lot of things about you – you as a player, you as a person, the whole nine yards.”

Not to read too much into his words, but he sounds like a guy whose identity is inexorably linked to his ability to hit a baseball, and that will either be the secret to his success or the fatal flaw that keeps him from achieving his full potential.

I think the Mariners mishandled his promotion last season. It’s not so much that he wasn’t ready but the spot they threw him into. Remember that when he was called up, they were struggling badly to hit, and they didn’t exactly ease him into the lineup. They batted him leadoff right away. How could he not feel the pressure to perform? For a kid who is prone to gripping the bat too tight, he was not set up to succeed.

This spring started slowly once again for Kelenic. He hasn’t lit it up like his pal Julio. He’s likely to see more time at the corner spots as Julio takes more reps in center field. And while the numbers haven’t looked good, his GM said his at-bats have been fine and he is driving the ball the other way, a sign that he is relaxed and swinging free and easy.

Let’s hope that good approach leads to some results, because Kelenic seems like the kind of player who can really build off his own success. And while Julio will get a season to make his rookie mistakes, Kelenic will feel a little more pressure to perform this year. The 2022 Mariners are built to handle Julio’s ups and downs, but they’ve had Kelenic written in pen. They are counting on him.

I also wonder how Kelenic will handle Julio’s ascension. While they have been linked for years, he was always ahead because of his age. How will he handle being caught – or passed – by his partner? Will he allow that doubt to creep back in? Will he thrive without the perceived pressure to carry the team?

Kelenic seems like a bright kid with a good head on his shoulders and the family support to help him through anything. I have a lot of faith that he will rise to the occasion, and I hope he does. Because nothing would mean more to this team this year than him building on last year.

And if he and Julio turn out to be on the level of some of those great dynamic duos, well, I think Mariners fans know what kind of future they could expect.

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