ST. PETERSBURG -- The way the Rays began the season set an almost impossibly high standard. They won each of their first 13 games and 29 of their first 36. They went almost a month without losing consecutive games at home. Their first three-game losing streak came nearly halfway through their regular-season schedule.

But slumps are inevitable, even for the best team in the American League.

“We're going to hit some tough stretches,” manager Kevin Cash said before the Rays’ 8-4 loss to the Phillies on Wednesday night at Tropicana Field, “and it feels like we've been on one.”

After giving up 17 hits to a streaking Philadelphia lineup, Tampa Bay has lost four straight games for the first time all year. This is also just the second time the club has lost back-to-back home games. Having dropped 13 of their past 23 games, the Rays have struggled just to tread water lately.

“Everybody in here knows we're not playing our best ball, but we know that comes with a season that's 162 [games],” infielder Taylor Walls said. “We'll get back to it. But luckily, it's happening now so we can clean some of those things up, find some of the weaknesses that we [have] now and get better at them, so later on down the road, we're a lot stronger.”

After being on the wrong end of a pitchers' duel in the series opener, the Rays were outplayed in all facets on Wednesday night by a Phillies club that has won 21 of its past 28 games.

Tampa Bay scored early against starter Taijuan Walker, putting up four runs in the first three innings, but its pitching staff had blown three leads by the fifth inning. Then, the Rays' bats went quiet, managing only three walks and two singles from the fourth inning onward as Walker settled in to pitch seven innings to earn his sixth straight win.

“He's just a good pitcher. He was out there executing his pitches, getting guys to swing and expand the zone,” said Brandon Lowe, who went 2-for-3 with two doubles and two RBIs. “Honestly, he was just a professional arm out there.”

Meanwhile, the Rays sent six pitchers to the mound; only two of them, lefty relievers Jake Diekman and Colin Poche, didn’t allow a run. Opener Zack Littell gave up four straight hard-hit singles to permit two runs in the second inning, then right-hander Yonny Chirinos -- coming off a strong six-inning performance in Arizona -- allowed three runs on eight hits while covering only 2 2/3 innings.

“It felt like we were kind of -- not giving it back, but they were coming back,” Cash said. “Then, they ultimately took the lead and didn't look back. A lot of good at-bats by them.”

Chirinos’ relatively brief outing forced the Rays to lean heavily on their relievers the night before another scheduled bullpen game. Shawn Armstrong will open Thursday’s series finale, and while the club will likely call up another pitcher from Triple-A Durham, the relievers will have had to do a lot of work heading into this weekend’s series against the MLB-leading Braves.

The Phillies put 14 balls in play against Chirinos, and seven of them came off the bat with an exit velocity of at least 95.5 mph, according to Statcast.

“I was just trying to attack their hitters. They're a really good team, so they were attacking me back,” Chirinos said through translator Manny Navarro. “When you do that, sometimes you have good results, sometimes you have bad results. But my goal is to just keep on working and just learn from it.”

As frustrating as this stretch has felt, the Rays’ incredible start to the season gave them the ability to withstand it, to a certain extent. Their 57-32 record is still the best in the AL. They remain five games ahead of the Orioles (50-35) in the AL East, having lost only 1 1/2 games off their division lead during this 10-13 slump.

Tampa Bay knew a slump like this would happen at some point. What matters now is how the Rays respond to it.

“Everybody in here has been through it before -- individually, as a team. This is pretty much the same core guys that were here last year, and we went through it last year and we had some tough stretches,” Walls said. “Guys are going to have the right mentality to come in, get their work done, know how to weather through the storm, I guess you would say, and come out on top.”