Phillies may decide to rest Zack Wheeler through the All-Star break after his lower back injury

After exiting early Tuesday night with a tight lower back, Zack Wheeler said he planned to start Sunday, as scheduled.

Not so fast.

Wheeler went for an MRI exam on Wednesday, and although the test didn’t indicate structural damage, according to manager Rob Thomson, the Phillies are talking about giving their ace an extended All-Star break to ward off a more serious injury.

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“We’re going to be very precautious with him,” Thomson said. “We’re not going to risk anything.”

Especially given the circumstances. With the best record in baseball and a comfortable lead in the division, the Phillies’ highest priority between now and October is to keep as many players — starting pitchers, in particular — as healthy as possible.

Wheeler gave up one run in five innings Tuesday night against the Los Angeles Dodgers. He looked dominant at times, striking out Shohei Ohtani on three pitches to open the game and piling up seven strikeouts overall. His fastball maxed out at 97.6 mph.

But Wheeler also reported tightness in his left lower back. So, after only 76 pitches and with the Phillies leading by eight runs, he was lifted before the sixth inning.

Wheeler conceded that his back has “bothered me here and there a little bit lately.” He thinks he might have tweaked it during a June 27 start at home against the Marlins and has received treatment in between his last three starts.

Is there reason for the Phillies to be concerned?

“I don’t know,” Wheeler said Tuesday night. “Just got to take it day by day and see how it goes. I plan on making my next start.”

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Sure, but the Phillies can skip Wheeler’s turn Sunday and give him more rest around the All-Star break. Despite being selected for the All-Star Game, he’s ineligible to pitch because he’s lined up to start the final game before the break.

The Phillies could replace him Sunday with rookie Michael Mercado. Or, as Thomson indicated, they could arrange a bullpen game, which might even be a desirable option entering the All-Star break.

“It just happens really on the perfect day, the day before the break,” Thomson said, “because you can get all your bullpen arms to throw in the game and that way they don’t have five days off coming out of the break.”

And the argument for having Wheeler face the Oakland Athletics on Sunday?

“Just that you’ve got Zack Wheeler going out there,” Thomson said.

Sure, but that’s also a good reason to be conservative. Through Tuesday, Wheeler was second in the National League with a 2.70 ERA. He ranked second in the league in innings (116⅔) and opponents’ batting average (.192), third in WHIP (0.99), and fourth in strikeouts (126).

The Phillies have done well to keep their top starting pitchers healthy over the last two seasons, save for Ranger Suárez’s delayed start last year because of an elbow injury while preparing for the World Baseball Classic. Wheeler and Aaron Nola rank third and fifth in innings pitched since the start of last season.

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Meanwhile, the other NL superpowers are dealing with key injuries to their rotations. The Dodgers have Yoshinobu Yamamoto (shoulder), Tyler Glasnow (back), Walker Buehler (hip), and Clayton Kershaw (shoulder) on the injured list. Atlanta Braves ace Spencer Strider is out for the season after Tommy John elbow surgery.

So, even though Thomson defined Wheeler’s injury as “just back spasms, really,” the Phillies won’t take any chances.

“That’s why we’re going to be precautious,” Thomson said. “I’m not really concerned. He’s been through this before. He’s going to be fine. It’s just back spasms, really, so I’m not really concerned. We just want to make sure we take care of him.”