The Mariners received some major validation to their blossoming farm system on Thursday when MLB Pipeline revealed its Top 100 prospects entering the 2021 season.

Headlining that group were outfielders Jarred Kelenic and Julio Rodríguez, who were listed Nos. 4 and 5, respectively, becoming the Mariners' highest-ranked prospects since Felix Hernandez was No. 3 in 2005.

• The complete Top 100 list

Seattle had six players represented in the new rankings, marking the first time since MLB Pipeline began ranking in 2012 that the club had that many in the Top 100:

4. Jarred Kelenic, OF (ETA: 2021)
5. Julio Rodríguez, OF (ETA: 2022)
31. Emerson Hancock, RHP (ETA: 2022)
33. Logan Gilbert, RHP (ETA: 2021)
92. George Kirby, RHP (ETA: 2021)
100. Taylor Trammell, OF (ETA: 2021)

• Mariners’ Top 30 prospects list

Only the Rays, with eight, had more players represented on the 2021 list. The Mariners’ previous high was five in ‘13: right-hander Taijuan Walker (No. 5), left-hander Danny Hultzen (No. 18), catcher Mike Zunino (No. 23), shortstop Nick Franklin (No. 47) and left-hander James Paxton (No. 61).

The rankings offered external affirmation of general manager Jerry Dipoto’s multi-year rebuild, a process that began as a “step back” following an 89-win season that left Seattle out of the postseason in 2018, to one that the club is being “patient” with heading into ’21 after many in its pipeline experienced stalled development due to the cancellation of last year's Minor League season.

• The Top 100 prospects for '21, team by team

Since taking over as GM following the 2015 season, Dipoto has gone from wheeling and dealing to bolster the big league roster, to putting a huge premium on the pipeline. Despite his aggressive track record early in his Seattle tenure, Dipoto has been mostly quiet on the Major League front since the step back in ’18, which unofficially began when the club acquired Kelenic from the Mets in the Robinson Canó/Edwin Díaz deal that winter, which was the most recent blockbuster of Dipoto’s tenure.

Kelenic has the potential to be a star, with MLB Pipeline scouting reports suggesting he “should be a right fielder who hits .280 with 20 homers on an annual basis. He comes with a lofty ceiling too, as he could be a center fielder who wins batting titles and posts 30-30 seasons." Mariners hitting coach Tim Laker went further to suggest Kelenic’s floor might even be higher.

“You don’t see that many guys get into pro ball and just hit from Day 1 and just move up the way he has and put up the kind of numbers. That’s why you see him so high on the prospects list,” Laker said. “I think he’d like to hit for power, but he’s not going to be happy hitting .270, .280. He’s a guy I think just with the way, as good as he thinks he can be, he’s not going to be satisfied unless he’s hitting .300. I know he does want to hit for power, but I don’t think he’s going to be a guy that’s going to get too caught up or consumed with it where it takes away his ability to be a complete hitter."

Dipoto and McKay have both said publicly that Kelenic will make his debut in 2021 -- but they’ve been tight-lipped as to when. Kelenic posted a .291/.364/.540 slash line with 23 homers in his last full season in 2019, but he’s never played above Double-A.

Rodriguez also oozes with power potential that the Mariners haven’t seen in the outfield since Hall of Famer Ken Griffey Jr. manned the cavernous Kingdome.

"He's an advanced hitter for his age with plenty of strength and bat speed, and he could produce 40 homers per season once he starts driving the ball in the air more consistently,” MLB Pipeline’s Jim Callis wrote.

Rodriguez is likely a year behind Kelenic, having topped out at Class A Advanced in his last full season, when he slashed .326/.390/.540 with 12 homers across 84 games between two Minor League affiliates. But he is just 20 years old and still has room for improvement with his baserunning and defense, as well as adjusting to Major League pitching.

• Julio looks, sounds every bit like big leaguer

Kelenic and Rodriguez manning an outfield with reigning American League Rookie of the Year Award winner Kyle Lewis has some in baseball circles suggesting that Seattle could have one of the more dynamic outfields in the coming years.

“I cannot even explain right now how excited I was when I saw [Lewis] balling out there,” Rodriguez said. “We have the talent. We’re going to put the work out there. It’s going to be a fun outfield to watch.”

Mariners manager Scott Servais is quick to remind fans not to sleep on fellow outfielder Trammell, who the skipper recently said was one of the players he was most excited to see in big league camp after Seattle acquired the outfielder from the Padres last summer.

• Top prospects highlight Mariners' NRI list

There’s also been a significant influx of pitching to the pipeline, as was represented in Thursday’s rankings. Hancock, the club’s first-round pick in 2020, tops that group, but he won’t be in the mix to contribute this season. But Gilbert, who checked in two spots behind, will vie for Major League innings, with the Mariners needing an army of arms among its inexperienced group that is rebuilding its workload following a shortened season.

Kirby, the club’s first-round pick in 2019, is further behind than Gilbert and will begin ’21 in the lower Minor League ranks.

For as much hype as Kelenic and Rodriguez have received, the success of the Mariners in the next five years could hinge heavier on its pitching nucleus of Hancock, Gilbert and Kirby -- all of whom are touted as frontline Major League starters.

While some might point out that the club has felt on the verge of contention before with lofty prospects -- particularly given that the club is mired in the longest postseason drought in American professional sports -- Thursday offered some tangible validation to the Mariners’ rebuild, and that it’s headed in a promising direction.

"We've termed this as waves of players coming, and I do expect another wave of prospects to make it onto our roster at some point this season when they're ready," Servais said. "That's exciting, because I know the talent that these guys have. But also understand that it sometimes takes a little bit of time to get adjusted to the speed of the game and what's going on in the big leagues and whatnot.

"What allows these players to make that adjustment even quicker is the group that's already here. The group that we're talking about, they're young in their own right but they understand what they just went through and the value of making those new players feel like they're a part of a team, part of our future."