The Orioles welcomed Samuel Basallo to the big leagues in a big, big way.

According to ESPN’s Jeff Passan, the team is completing a landmark eight-year, $67 million contract with their rookie catcher, just days after his Major League Baseball debut.

Basallo’s deal will kick in for the 2026 season and can max out at $88.5 million — the largest pre-arbitration extension for a catcher, per Passan.

The 21-year-old from the Dominican Republic made his first appearance for the Orioles on August 17 and has since gone 4 for 14 with five RBIs, posting a .286/.333/.357 slash line over four games.

This is an impressive beginning for the left-handed hitter, who signed what was then an organizational record $1.3 million international contract in 2021 and has climbed to the No. 9 prospect in all of baseball, according to MLB rankings.

He quickly climbed the organizational ladder, reaching Triple-A as a 20-year-old after going from Low-A to Double-A in 2023.

He arrives in Baltimore after posting a .270/.377/.590 slash line with 23 homer runs and 67 RBIs in 76 games with Triple-A Norfolk this season.

He’ll also get an early chance to stake his claim behind the plate with incumbent backstop Adley Rutschman on the IL with an oblique strain for the second time in three months.

Rutschman, cited by The Post’s Jon Heyman as a top trade candidate this coming offseason, is in the midst of his worst offensive season as a pro.

With the 27-year-old shelved, Basallo can stake his claim on the position with the Orioles in an intriguing position at the end of a lost season.

He’ll have to work on his defense, a rough part of his game as noted by MLB scouts, though his “cannon” of an arm is a major positive.

The team could opt to play him at first base or designated hitter, as well.