Nationals third baseman Anthony Rendon fields the throw as the Phillies' Carlos Santana slides safely into third for a triple during the sixth inning. Rendon went 0 for 2 with two walks Saturday. (Carolyn Kaster/AP)

Anthony Rendon emerged from the back of the clubhouse to find an eight-piece mariachi band serenading the Washington Nationals on Saturday morning.

It was Cinco de Mayo, and Rendon had been officially activated from the disabled list a little earlier in the day. His manager wanted a dance performance to celebrate the events. So Dave Martinez, the enthusiastic mastermind behind the festivities, summoned his starting third baseman to the middle of the room. Rendon, whose father is of Mexican descent, complied, putting some moves together to “Cielito Lindo.”

“He’s back!” teammates yelled over the violins, trumpets and guitars. “Tony’s back!”

Rendon was indeed back. After a strange three-week absence that began with a nine-day delay between his injury and the beginning of his DL stint, the Nationals’ 2017 MVP candidate was in the lineup and batting second Saturday even though a hairline fracture in his left big toe, which the Nationals hid until Rendon admitted Friday there was a fracture, hasn’t completely healed.

In theory, his return would provide a jolt for Washington. In actuality, his return prompted Martinez not to include Trea Turner and Michael A. Taylor, who needed breathers, in Saturday’s starting lineup before Ryan Zimmerman was scratched from it with stiffness in his side. The outcome was a shorthanded lineup the Nationals probably will never field again, and it couldn’t muster much in a 3-1 loss to the Philadelphia Phillies that snapped a six-game winning streak and dropped Washington (17-17) back to .500.

The Nationals went four innings without a hit against right-hander Vince Velasquez and managed just two for the game. As a result, they couldn’t capitalize on the eight walks and one hit-by-pitch the Phillies gifted.

“I tip my hat to Velasquez,” Martinez said. “Really. He pitched well. Their bullpen came in and pitched well.”

While Washington stumbled, the Phillies (18-14) pounced on Tanner Roark immediately, scoring two runs two batters into the game after Cesar Hernandez walked and Rhys Hoskins socked a 3-2 fastball for a home run. Roark wasn’t as sharp as usual — he backed his way into three-ball counts often early — but he managed to keep the Phillies off the board again until the sixth inning. Philadelphia tacked on a third run then, after Carlos Santana tripled and Maikel Franco singled to drive him home.

Roark went on to log 6⅓ innings on a season-high 115 pitches. He allowed three runs on six hits with three walks and nine strikeouts. That would have secured a victory on most days. But the Nationals’ offense, so good against right-handed pitching most of the season, faltered against five righties Saturday, beginning with Velasquez.

“I go until they take me out of the game,” Roark said. “I just dug deep and, like I said, gave the best I got for the 115 pitches that I threw.”

Washington finally broke through against Velasquez in the fifth inning, when Wilmer Difo smashed his second home run of the week to break up Velasquez’s no-hit bid and extend his hitting streak to eight games. The homer, however, didn’t jump-start the Nationals’ offense even as Velasquez’s pitch count hiked and Philadelphia turned to its bullpen after five innings. Four Phillies relievers combined to hold the Nationals scoreless over the final four innings.

The Nationals appeared poised to snap out of it in the ninth inning, when Turner, pinch-hitting, led off with a walk against the erratic Hector Neris. Then a gaffe cost Washington. Matt Wieters, also pinch-hitting, hit a popup to shallow right field while Turner was running on the pitch. Hernandez, the second baseman, made the easy catch, but Turner, who had slid into second base headfirst, stood up at the bag not realizing the ball was hit in play. He was doubled off before he could even try running back to first base. Two batters later, the game was over.

“Usually, I hear the ball off the bat, so a lot of times if I hear it, I’ll look up,” Turner said. “I didn’t hear it that time.

Rendon, meanwhile, finished 0 for 2 with two walks. His first major league at-bat in 22 days began with a sustained ovation from the 34,687 in attendance for “Star Wars Day” as he walked to the plate with heavy armor protecting his left foot. It ended with him in disbelief over home plate umpire Mike Muchlinski’s decision to call strike three on a checked swing without seeking help from his colleague behind first base.

His second appearance came with two outs in the third inning with the Nationals still without a hit off Velasquez but with a runner at first after a hit-by-pitch. Rendon worked an eight-pitch walk to extend the inning for Matt Adams, who struck out on a checked swing to end Washington’s best scoring opportunity.

Rendon’s only test on defense surfaced in the fourth inning, when Franco laced a groundball his way. Rendon backhanded it and made the play with ease. He later walked and grounded out in his final two at-bats. After the game, he dodged questions about the return, giving unrelated answers about the game.

“He looked good,” Martinez said. “He looked real good. . . . Ran well. So he’ll be out there tomorrow [Sunday].”

It was an uneventful, though positive, return after a festal prelude, which included the mariachi band giving a second performance while Washington took batting practice. It wasn’t the first time Martinez devised a lighthearted diversion to interrupt the season’s monotony. He had camels visit, arranged a golf competition and hired bagpipe players for St. Patrick’s Day during spring training. Recently, he has planned viewing parties for Washington Capitals playoff games when he’s not attending them himself. Martinez is doing his best to keep his bunch loose. Having key players return helps. It just didn’t help much Saturday.