HOUSTON -- Already dealing with significant injuries to star players George Springer and José Altuve, the Astros suffered another blow Wednesday when it was revealed All-Star shortstop Carlos Correa would miss four to six weeks after breaking a rib while getting a massage at his home Tuesday.

The injury is a significant setback to an Astros club that saw Springer, an early American League MVP candidate, and infielder Aledmys Díaz both go down with left hamstring strains this week. Altuve, who strained his left hamstring May 10, was rehabbing his injury at Triple-A Round Rock on Monday when he came down with right leg fatigue, meaning he could be out a couple more weeks.

“It’s a tough loss for us,” Astros manager AJ Hinch said of losing Correa. “It’s certainly tough for him. There’s not much we can do about it now. He’s going on the IL. He’ll be gone for a significant period of time, and we’ll have to adjust as a team and play well in his absence.”

The Astros called up infielder/outfielder Myles Straw from Triple-A Round Rock to replace Correa, but president of baseball operations and general manager Jeff Luhnow admitted Wednesday the team will explore trade opportunities with three core position players out.

“It’s going to be a challenging time for our club,” Luhnow said. “We have six or seven players right now who aren’t able to play, and that’s frustrating for the month of June. We had a great start to the season, but it’s going to challenge our depth, it’s going to challenge our ability to be creative and we’re going to have to keep playing well. I think we can do it with the talent we have, but we’re going to have to explore all options, including potentially bring in help from the outside.”

Correa, who was debilitated by a back injury in the second half of last season, was having a terrific rebound season in which he was hitting .295 with 11 homers, 35 RBIs and a .907 OPS. He wasn’t at Minute Maid Park on Wednesday because he had to limit his activity. He released a statement through the club.

“I’m extremely disappointed about not being on the field with my teammates,” he said. “I sustained the rib fracture during a massage at my home on Tuesday. To sustain an injury in such an unusual way makes it even more frustrating. However, I will work hard to get back on the field as quickly as possible to help our team achieve our goal of winning another championship.”

The Astros have their own masseuse on staff, but Luhnow said it’s not against team policy for players to seek their own treatments.

“It’s not uncommon for players to seek some sort of therapy outside of our group, and that’s something that’s always been the case,” he said.

With Correa, Altuve, Springer, Diaz and backup catcher Max Stassi on the injured list, the Astros have four position players on their roster who were in Triple-A a week ago -- outfielder Derek Fisher, infielder Jack Mayfield, catcher Garrett Stubbs and Straw, who has appeared in 25 games at shortstop and 23 in center field for Round Rock while hitting .289. Straw is ranked by MLB Pipeline as the Astros' No. 14 prospect.

“We’re going to have some combination of the Houston Astros and Round Rock Express playing in the month of June,” Luhnow said. “We’re going to mix and match, and I’m going to leave it up to AJ and [bench coach Joe] Espada to evaluate Straw and see if they feel he can help in the infield. We knew he’s a great defensive center fielder and outfielder and a right-handed bat, which fits well.”

Meanwhile, Altuve will have to undergo strengthening and stabilization exercises in both legs and both knees. Luhnow said Altuve could be out another 10-14 days before starting a Minor League rehab, though no timetable is firm.

“He really needs to just focus on building strength in his right leg, and that could take days, could take weeks,” Luhnow said. “There’s nothing structurally wrong with his knee. He had it repaired last year, and it looks good. We checked it a few times. He pushes off that leg with his swing, so it’s really important he feel a solid foundation, and he just hasn’t quite felt that yet.”