ATLANTA -- The Padres never wanted to envision an infield without Fernando Tatis Jr. at shortstop. That’s why they promoted their 20-year-old top prospect to the Opening Day roster last month -- to the surprise of many.

Much to their dismay, the Padres will be without Tatis after all. The team placed him on the 10-day injured list Tuesday with a left hamstring strain. An MRI revealed no structural damage, but manager Andy Green said there’s no timetable for Tatis’ return, only saying that the rising star shortstop would miss “a number of weeks.”

“Exactly how many weeks depends on how he responds,” Green said.

The nature of hamstring injuries is that they can be murky in the immediate aftermath. Tatis reported a freer range of movement on Tuesday, two days after he sustained the injury on Sunday in Washington while stretching to corral throw. He did the full splits at second base in the process, and he came up hobbling.

"We care a lot about him, we think a lot of him, we love the way he's started his big league career," Green said. "We're going to take care of him. We're going to put him in the position where he has his best shot at health for a long period of time."

Tatis was off to a flying start for the Padres, hitting .300/.360/.550 with six homers while playing an outstanding shortstop. He's been the spark for San Diego's hot start over the season's first month.

“He’s been our offensive catalyst, probably our most consistent performer from the first day to the day he got hurt,” Green said. “Defensively, he’s locked down a tough position to play. … He’s been right in the middle of a whole lot of [wins].”

In Tatis’ absence, the Padres will turn to Manny Machado at shortstop. That means recent callup Ty France will man third base regularly, with playing time at second base split between Greg Garcia and Ian Kinsler.

If that duo continues to struggle -- and if Luis Urías continues to rake at Triple-A El Paso -- it’s easy to envision a callup for Urias, the team’s No. 3 prospect. But that won’t happen for at least a couple days.

The Padres promoted righty reliever Phil Maton in Tatis’ place on Tuesday, and Cal Quantrill will be added to the big league roster on Wednesday as part of a temporary six-man rotation. The Padres will carry a short bench for those two games, but they expect to promote a hitter on Thursday.

As for Machado, he has plenty of experience at short, having played there last season with the Orioles and Dodgers. With Tatis out, Machado slid to shortstop in the late innings on Sunday and Monday. In each game, he made an outstanding defensive play to prevent meaningful runs from scoring.

“He’s going to lock that spot down for us and play there consistently,” Green said. “What a weapon to have.”

Machado’s temporary move to shortstop means an opportunity for France. The slugging 24-year-old was promoted last week, but he didn’t have an obvious position in the infield.

Instead, France served as a pinch-hitter in each of the past four games, while taking pregame reps at second base for a potential move there. Now, the San Diego State grad will get his game reps at third, where he’s spent most of his pro career. France received his first start on Tuesday night, and he batted fifth.

If France proves himself over the next few weeks, it might give the Padres something of a logjam when Tatis returns. That’s a problem they’d love to have, because it means Tatis will have returned. That process won’t be rushed.

“Obviously, as an organization, he means a lot to us,” Green said. “He means a lot to our future. We’re not going to be cautious just to be cautious. We’re going to make sure he’s ready to take every step. Hopefully, he’s back relatively quickly.”