PHILADELPHIA -- Taijuan Walker is the No. 5 starter on a talented Phillies team with World Series aspirations; they only need him to give them a chance to win every five days.

Just keep it close.

Walker allowed three runs in 4 2/3 innings in Sunday afternoon’s 6-4 loss to the Nationals at Citizens Bank Park. The Phillies still had a chance to win in the ninth, bringing the tying run to the plate with no outs, but Cal Stevenson grounded into a double play before Garrett Stubbs grounded out to end the game. Phillies manager Rob Thomson had Bryce Harper and J.T. Realmuto on the bench, but had no plans to use them.

“Absolutely,” Thomson said when asked if it was difficult not to use two of his best hitters. “But I’m thinking long-term as well.”

Thomson said before the game that he gave Harper and Realmuto the day off because of their recent workloads. Still, it was only natural to think Harper might hit in the ninth.

Thomson said his “long-term” philosophy could change eventually, but he has stuck to it this year. The Phillies have only 63 pinch-hit at-bats, which ranks 26th in baseball, ahead of the Nationals, Braves, Rockies and Yankees.

“It depends on the day and where we’re at and how many games they’ve played in a row, how their bodies are feeling,” Thomson said. “There are a lot of factors.”

The Phillies are 4-1 since holding a team meeting Wednesday afternoon. They have a 7 1/2 game lead over the Braves in the NL East as of Sunday, and while they have played better of late, they will get a better test this week on the road against the Braves and Royals.

Still, the feeling in the clubhouse is that the worst might be behind them. Their starters have pitched better recently. Zack Wheeler, Aaron Nola and Cristopher Sánchez allowed a combined two earned runs over 21 2/3 innings in their last starts.

Walker, Nola and Sánchez are scheduled to pitch this week in Atlanta, although Sánchez could be pushed back a day if he is experiencing any lingering effects from Saturday’s complete game. If he doesn’t pitch Thursday, it will be a bullpen game.

If he does pitch Thursday, Walker could start Friday, while Ranger Suárez could rejoin the rotation on Saturday.

Walker has allowed six runs in 8 2/3 innings in two starts since rejoining the rotation, while striking out eight and walking six. He allowed a two-run home run to Keibert Ruiz in the fourth inning to tie the game -- it was a 0-2 sinker high and outside. It wasn’t close to a strike.

In fact, the switch-hitting Ruiz homered on a pitch that was 4.07 feet off the ground and 0.62 feet from the center of home plate, according to Statcast. He joined teammate CJ Abrams as the only two left-handed batters since 2015 to pull home runs on pitches that were at least that high and that far outside (Abrams did it on Aug. 6).

“Initially, I thought it was in the zone,” Walker said. “Then when I saw the replay I saw that it was way out of the zone. It's kind of what he does though. 0-2 pitch, it's one of those where I've got to tip my cap I guess.”

Walker remains a work in progress. He thinks he will be better in time and pitch deep into games again. His four-seam fastball averaged 92.2 mph on Sunday. He threw his hardest one in the fifth inning at 93.8.

He threw his five hardest pitches in the fifth, actually.

He also threw a season-high 41 splitters out of 99 total pitches. It was his highest splitter usage (41 percent) since Sept. 17, 2023. Walker needs to throw a good splitter to be effective. He got only three whiffs on 17 swings (17.6 percent) on Sunday.

His splitter’s whiff rate is down considerably from the past three years.

“Just getting comfortable, throwing the splitter a lot more,” he said. “I want to throw it down, I want to throw it under the zone. But I just have to trust that the splitter is back, it’s good and I can throw it up in the zone and get weak contact with it.”