SAN DIEGO -- The knuckleball lives.

The Padres, in need of a spot starter Saturday against the Nationals, plan to promote 26-year-old right-hander Matt Waldron -- who will become the first regular knuckleballer to pitch in the big leagues since Mickey Jannis did so for the Orioles in 2021.

“It fulfilled the dream I’ve had my whole life,” said Waldron, who joined the Padres’ taxi squad Friday. “... I don’t even know if it’s hit yet.”

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Waldron's callup comes with the Padres planning to skip Michael Wacha's start while he deals with right shoulder fatigue. Manager Bob Melvin noted the team is confident Wacha will return to the rotation for his next turn.

That left an opening for Waldron, whose arsenal also features a fastball and a slider. He is not a knuckleballer in the mold of, say, Tim Wakefield or R.A. Dickey, righties who relied almost exclusively on the pitch. 

But the knuckleball is a primary weapon for Waldron, and his arrival in the big leagues heralds the return of one of baseball’s most whimsical offerings -- a pitch that, in recent years, has bordered on extinction.

The 2021 season saw Jannis throw 57 knuckleballs in his lone appearance. Aside from the occasional position player pitching, Statcast has not tracked a knuckleball since. Over the past five seasons, only Jannis, Ryan Feierabend and Steven Wright have thrown regular knuckleballs. The Padres haven’t had a regular knuckleballer since Charlie Haeger in 2008.

Waldron’s knuckler sits around 80 mph – harder than most. He has struggled this season in the hitter-friendly confines of Triple-A El Paso, where he has posted a 7.02 ERA across 14 appearances. He notched a 2.84 mark the previous season at Double-A San Antonio. There’s some speculation that perhaps the pitch simply plays better at sea level.

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In any case, it’s wholly unclear what to expect from Waldron on Saturday, including just how frequently he will throw the pitch. With the notoriously unpredictable movement of a knuckleball, Melvin noted that Gary Sánchez will have the unenviable task of catching Waldron.

A former catcher himself, Melvin broke it down thusly: “You see it, you feel pressure, you squeeze.”

Waldron, an 18th-round selection by the Guardians in the 2019 MLB Draft, was the player to be named later in the 2020 trade that landed Mike Clevinger in San Diego and sent Josh Naylor and Cal Quantrill to Cleveland. Waldron messed with a knuckleball before his arrival, but it wasn’t until summer ’21 with the Padres that he began using the pitch with regularity, after the organization encouraged him to do so.

Waldron learned the news of his big league callup on Thursday when he was presented a scouting report on the Nationals lineup by Triple-A pitching coach Scott Mitchell, who asked, “How are you going to attack these guys?”

The answer: Differently than any other big league pitcher.