SAN DIEGO -- Now that he’s arrived and established himself as a budding superstar, the Padres don’t want to envision life without Fernando Tatis Jr. 

They got a taste of it Tuesday night, and it wasn’t pretty. Tatis exited a tie game in the seventh inning because of a lower back spasm. Things unraveled on the Padres from there, and they dropped their third straight, a 7-5 loss to the Rays at Petco Park.

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That skid took a backseat to the status of Tatis, who will be out at least through Wednesday afternoon’s series finale. The Padres are hopeful that he’ll be healthy enough to return Friday, when the club opens a three-game series in Philadelphia.

“He's just got some soreness back there,” Padres manager Andy Green said. “We won't start him tomorrow, and that gives him two days off. We'll see how he is after the off-day. Hopefully it's nothing more than that. Sometimes over the course of 162, you get a little sore and stiff.”

During his at-bat in the bottom of the sixth, Tatis fouled off an 0-1 curveball from Rays right-hander Nick Anderson, then immediately clutched his lower back, which prompted Green and a team trainer to spring from the dugout.

Tatis remained in the game temporarily, only to strike out two pitches later. Then, he retreated to the clubhouse for further evaluation. After going 2-for-4 to bring his average to .317, Tatis’ night was done. 

“He felt it -- you could see with the way he responded to the swing,” Green said. “He said he was OK. After he finished that at-bat, it still didn't look right. We tried to exercise a little bit of caution.”

Injuries, it seems, are the only thing capable of slowing Tatis’ meteoric rise. He missed a month from May into June while battling a left hamstring strain. It wasn’t until Sunday that Tatis again qualified for the league leaderboards. He’s looking to become the youngest batting champion in baseball history, and his .969 OPS ranks ninth in the Majors. 

In Tatis’ place, fellow rookie Luis Urias moved from second base to short, and Greg Garcia slotted in at second. Green indicated that’s the likeliest plan moving forward for as long as Tatis is out. Urias spent significant time at shortstop in the Minors, and he’s regarded as an average defender there.

Adding insult to Tatis’ injury, Padres right-hander Michel Baez surrendered a go-ahead two-run homer to Ji-Man Choi a few moments after Tatis left. Eric Sogard would tack on an RBI double in the frame as well.

San Diego clawed a run back and twice brought the go-ahead run to the plate in the eighth. Green opted to pinch-hit with Josh Naylor against Rays lefty Jose Alvarado -- preferring that matchup to a likely showdown between righty Ian Kinsler and righty Emilio Pagan.

Alvarado threw Naylor seven pitches out of the strike zone, according to Statcast. Naylor chased four of them, fouling off a high 2-2 fastball before swinging through a 3-2 slider that was well outside and probably low. 

Then, Rays manager Kevin Cash called for Pagan, who struck out Myers. San Diego hitters struck out a season-high 18 times.

The Padres’ three-game losing streak negated the three-game winning streak that preceded it, and they have again fallen nine games below .500 -- tying a season low. Now, they’ll hold their breath in hopes that their 20-year-old sparkplug won’t miss too much time. 

“Nobody thinks it's overly severe at this point,” Green said. “But they'll wait until he wakes up in the morning and find out how he feels. Hopefully, we'll hear the same thing again tomorrow. Sometimes with backs, you just don't know.

“You're always just crossing your fingers, hoping. He's obviously been a huge part of everything we've done this year.”