The biggest declaration of this young baseball season: Vladimir Guerrero Jr. now officially carries a very loud, very lethal and very powerful bat.

Guerrero launched three home runs and drove in seven runs in the host Toronto Blue Jays' 9-5 victory over the Washington Nationals on Tuesday. Two were off Max Scherzer, one of which was a laser-beam grand slam in the third inning that traveled 415 feet and had a 108-mph exit velocity.

That wasn't even his hardest or farthest home run of the night. In the fifth inning off Scherzer, Guerrero crushed one at 110.5 mph, 436 feet into the Florida night.

Guerrero is hitting .360/.484/.693 with seven home runs. At 22 years old, he became the youngest player ever with a three-homer, seven-RBI game. In the expansion era since 1961, only Boog Powell and Corey Seager were younger when they hit three home runs in a game. Vladimir Guerrero Sr., Vladdy's Hall of Fame father, never hit three home runs in a game. Dad was impressed with his son's historic game:

Avg.360

7 HR

19 RBI

Proud dad! ❤️#VG27

— Vladimir Guerrero (@VladGuerrero27) April 28, 2021

What a night for my boy. ?? All the hard work is paying off. ??#VG27

— Vladimir Guerrero (@VladGuerrero27) April 28, 2021

Senior can relate to one thing, however: He homered off Scherzer back in 2010, when he played for the Rangers and Scherzer was pitching for the Tigers, and again in 2011 when he was with the Orioles. The Guerreros join this list of father-son duos to homer off a Cy Young winner:

• Ken Griffey Sr. and Jr. homered off Dennis Eckersley, Bob Welch and Rick Sutcliffe
• Hal McRae and Brian McRae homered off Eckersley
• Jose Cruz Sr. and Jr. homered off Orel Hershiser
• Vern Law and Vance Law homered off Gaylord Perry

More than the fun factoids, however, this feels like a statement game.

When the 2021 season began, everybody had climbed aboard the hype train of young superstars: Fernando Tatis Jr., Ronald Acuna Jr. and Juan Soto -- with good reason. Guerrero wasn't considered on their level.

When Guerrero came up in 2019 at age 20, he was good at the plate but not great. Meanwhile, Soto came up in 2018 at 19, became an immediate star and then tore it up in the World Series in 2019. Acuna came up in 2018, became an immediate star and then hit 41 home runs and stole 37 bases in 2019. Tatis came up in 2019 and was a dynamo of power and speed.

Guerrero arrived in the majors as perhaps the most ballyhooed prospect since Griffey Jr. reached the majors as a teenager in 1989. He was viewed as the best hitting prospect in a long time. Scouts were comfortable putting an 80-grade tool on his bat. In the minors, he hit for average, hit prodigious home runs and did it all while rarely striking out. He also showed much better plate discipline than his dad, who was one of the more notorious free swingers in the history of the game.

In this Tik Tok world of short attention spans, we expected immediate greatness from Guerrero, forgetting that baseball is hard and that, despite the glowing debuts from Soto, Acuna and Tatis, most young players need time to figure out major league pitching.

In Guerrero's case, his biggest issue in 2019 and 2020 wasn't a lack of power -- it was getting to that power. He hit too many balls on the ground.

The ideal launch angle for line drives and home runs is generally between 13 and 20 degrees. As a rookie, Guerrero's average launch angle was 6.7 degrees. In 2020, it fell to 4.6 degrees. So even though his hard-hit rate ranked in the 93d percentile in 2020, he hit .262/.329/.462 with nine home runs in 60 games. Better than a league-average hitter, but not near the numbers the other three young sluggers put up.

Guerrero also realized he needed to lose weight. He hired a personal trainer in the offseason and came to camp 42 pounds lighter.

"One day, I woke up from bed, looked in the mirror and said, 'That's it,'" Guerrero said on a recent Zoom call.

He worked on lifting the ball and his average launch angle is up to 10.6 degrees. He's more athletic and agile in the field and at the plate. His top sprint speed last year was way down at the 17th percentile. It's at the 45th percentile this year. A lighter Vladdy is a better Vladdy.

One thing I had wondered about heading into the season was whether the evaluators had simply overrated Guerrero's ability to hit elite velocity. Maybe the bat speed wasn't quite what everyone believed. Check his numbers against pitches of 95-plus mph:

2019: .184/.380/.368, 21.6% swing-and-miss rate

2020: .192/.222/.231, 20.9% swing-and-miss rate

(MLB average in 2019-2020 on 95-plus pitches: .247/.333/.415)

And so far in 2021 for Guerrero:

.400/.600/.727, 13.0% swing-and-miss rate (as the MLB average has dipped to .212)

The third homer he hit on Tuesday came off a 96.7-mph fastball from Kyle Finnegan, the fastest pitch he's hit for a home run in his career. It's a small sample size, just 15 plate appearances and 11 at-bats, but the swing-and-miss rate is down, a good sign that the improvement against fastballs can hold.

The other significant improvement he's made is with his plate discipline. His chase rate is down from 24.6% last year to 18.8%, and in this age of strikeouts, he has more walks than K's. And keep in mind he's largely done this without much help in the lineup so far. George Springer has yet to play. Teoscar Hernandez hasn't played since April 8. Bo Bichette is hitting .241 with a .295 OBP and Cavan Biggio is hitting .210 (after a three-hit night on Tuesday).

This is the Vladimir Guerrero scouts projected back in 2018 when he hit .381 in the minors: One of the best hitters in the game. Maybe even an MVP candidate. Make room on that train.