Many baseball fans might have missed it, given that it was a Sept. 16 matchup between two last-place teams, but one of the most exciting moments of this past weekend happened in San Diego. Padres catcher Francisco Mejia hit a walk-off grand slam: 

Mejia was considered a top-20 prospect in all of baseball entering the season and Baseball Prospectus even had him at No. 5. He's a career .293/.347/.452 hitter in the minors and looks the part of a very good to great starting catcher for quite a while. There's reason to be excited about Mejia alone, but the Padres actually have a pretty decent reason to be optimistic about a surge here in the next few years. 

Second baseman Luis Urias was a consensus top-40 prospect entering the season and got a cup of coffee this year. Unfortunately, he got hurt and won't play again this season, but he showed glimpses of his upside. In Triple-A this season, he hit .296/.398/.447 with 30 doubles, seven triples and eight home runs. 

The top prospect in the organization is a familiar name: Fernando Tatis Jr. MLB.com actually has him second in all of baseball behind Vladimir Guerrero Jr. and ahead of Eloy Jimenez. Tatis is only 19 and hit .286/.355/.507 with 22 doubles, four triples, 16 homers and 16 steals in 88 Double-A games this season. Check out this from MLB.com before this season: 

Tatis Jr. has all the ingredients to become an offensive force in the Majors, as his bat speed, leveraged swing and overall capacity to make adjustments all portend a future plus hitter with plus power. He proved vulnerable to spin and sequencing early in the year but tightened his approach as the season progressed en route to pacing the Midwest League with 75 walks. Many evaluators believe Tatis Jr. is merely scraping the surface of his offensive potential, as he still has considerable room to grow into his tall and athletic frame.

Hoo boy. 

Those three have the look of a strong nucleus of position players. The Padres already have some possible core pieces at the big-league level, too. 

We know Eric Hosmer was signed as the guy who can be the leader in the clubhouse who has been through the battles, with two pennants and one World Series ring under his belt. 

Hunter Renfroe is sporting an OPS+ of 120 with 23 homers in his age-26 season. We've seen what Wil Myers (age-27 season) can do when he's on. Austin Hedges (25) can be a great backup catcher to Mejia. 

Right fielder Franmil Reyes hit .324/.428/.614 in 58 Triple-A games and has a .276/.332/.516 line with 15 homers in 76 MLB games this season. Manuel Margot (23) is sub-par offensively, but he can run and plays good defense in center field. Franchy Cordero (23) has flashed some upside. 

What about the rotation? Well, Joey Lucchesi (25) has shown enough as a rookie to believe he can be part of it. He's pitched to a 3.67 ERA (105 ERA+) here in his first 23 starts. Jacob Nix (22) is getting a look in the rotation and has put together a few good starts, including on Aug. 28, when he only allowed one run in 8 1/3 innings. 

Left hander MacKenzie Gore was the Padres first-round pick (third overall) out of high school in 2017. Scouting reports indicate his future upside is a frontline starter, though he's only in Class A. 

Chris Paddack (22), on the other hand, isn't far away. The 6-foot-4 right hander was promoted to Double-A this season and pitched to a 1.91 ERA, 0.71 WHIP and 37 strikeouts against three unintentional walks in 37 2/3 innings. We might get a look at him next season. We could also see Logan Allen, a 21-year-old southpaw. He was good enough in Double-A to earn a promotion to Triple-A, where he had a 1.63 ERA in 27 2/3 innings. Lefty Adrian Morejon (19) had a 3.30 ERA in 13 starts in High-A this season. 

This is an awful lot of upside all over the diamond and on the mound. Hosmer and Myers make a lot of money, but not much of the rest of the roster does. It's possible the Padres could be players in free agency. Would they be able to make a serious run at Manny Machado? Third base is one of the positions not mentioned above. Maybe they convince him he can play shortstop for a few years before moving back to third or they simply put Tatis at third. If not Machado, what about giving Hosmer's old teammate Mike Moustakas a shot, should free agency go as badly as it did last time for him? Gambling on a Josh Donaldson turnaround? 

Obviously, we didn't cover every single possible name in the Padres organization that could be part of the turnaround here, but the  main takeaway is there are lots of reasons to believe the team is on the cusp of a breakthrough. Maybe 2019 is the "year before the year" like it was with the Phillies this year, as it turns out. Or maybe the Padres pull a Braves in 2019. It looks like it's coming and it's just a matter of when. 

Get excited, San Diegans.