SAN DIEGO -- A month into the season, the Padres sit three games above .500, in the thick of a tight National League West race, and wholly insistent that their best baseball is still to come.

“Our upside is tremendous,” said Padres manager Jayce Tingler. “I think we’ve only tapped into 40, 50, 60 percent of what we’re going to be.”

Bigger hurdles lie ahead. But a month into the Padres’ 2021 season, here are five things we’ve learned about them:

1. The rotation is elite, but not without questions

Padres starting pitchers combined to post a 2.67 ERA in April, the fourth-best mark in baseball. The three big-time arms acquired during the offseason -- Yu Darvish, Blake Snell and Joe Musgrove -- have lived up to the billing.

That's a recipe for October success. Line those starters up in a short series, and the Padres will be tough to beat, no matter whom they're facing. But getting to the postseason -- and finding the requisite arms to cover 162 regular-season games -- might prove tricky.

That's already becoming evident. Adrian Morejon is out for the season following Tommy John surgery. Dinelson Lamet (right forearm tightness) and Chris Paddack (unspecified) are on the injured list. Ryan Weathers exited his start early on Wednesday while feeling the effects of some arm fatigue.

"We know it's going to take more than a 26-man roster," said Tingler. "We're trying to be responsible, but at the same time playing to win. [We're] trying to think what's best short term, what's best long term, weighing those in trying to calculate risk."

That would seem to portend a MacKenzie Gore debut at some point, perhaps in the near future. The Padres were always going to be cautious with Lamet, and Weathers surely won't be asked to spend a full season in the rotation, having never reached 100 innings in the Minors.

2. The Padres will hold their own against L.A., but ...

The seven games between the Padres and Dodgers this season exceeded expectations -- and those expectations were already high. Every game was tight, and all seven games, it seemed, were decided by the slimmest of margins.

"We're going to fight these guys 'til the end," said Padres first baseman Eric Hosmer. "We respect what they've done. We respect who they are. But we're certainly not going to back down."

Sure enough, the Padres hold an early edge in the season series, four games to three. But it's notable that they entered May a game behind Los Angeles in the NL West standings.

The Padres have been at their best when facing the Dodgers. They haven't consistently been that version of themselves when facing the rest of the league.

3. Is Machado going for gold?

Manny Machado is a two-time Gold Glove Award winner and has been one of the best third basemen in baseball for a decade. Is it possible that he's getting even better?

"It's hard to imagine that he has elevated his defensive game," Tingler said. "But I would say through the first month of the season, that's what it looks like to me."

Machado has been a wizard at the hot corner, and he's starred in some of the Padres’ biggest moments, too, including a handful of excellent plays against the Dodgers.

Since moving to the National League, Machado hasn't yet won a Gold Glove. That's been Nolan Arenado’s for eight years running. Through April, the two sit tied atop the defensive runs saved leaderboard at third base with 3.

4. Tatis has lots of work to do defensively

Fernando Tatis Jr. is the ascendant face of baseball and the owner of the longest contract in the sport's history, so it's sometimes easy to forget the fact that he's 22 years old. But Tatis endured his share of growing pains last month -- particularly at shortstop.

After his remarkable defensive strides in 2020, Tatis committed a Major League-leading 10 errors in April. A handful of them came on relatively routine throws from shortstop.

Perhaps it was always unfair to draw any firm conclusions from last year's small defensive sample. The Padres remain staunch in their belief that Tatis is capable of being an asset defensively -- as his range and skill set would indicate. But he clearly has work to do to get there.

5. Melancon might be the best value signing in baseball

Mark Melancon's first month with the Padres was dominant enough. He pitched 13 innings, allowing one run, one walk and four hits, while converting all nine of his save opportunities. Not to mention, the underlying metrics give every reason to believe Melancon's hot start is for real.

Melancon signed an incentive-laden one-year, $3 million contract with the Padres, turning down bigger offers, he said, because he so desperately wants to win a World Series.

One month into his Padres tenure, Melancon is doing his part.