PORT ST. LUCIE, Fla. -- The Astros remain hopeful that ace pitcher Justin Verlander will be ready for the start of the season, which is less than four weeks away. The veteran right-hander cleared a significant hurdle on Sunday morning in West Palm Beach when he threw 60 pitches in the bullpen under the watchful eyes of general manager Dana Brown and manager Joe Espada.

Espada said Verlander threw some sliders and changeups to go along with his fastball without any issues. He talked with Verlander and pitching coach Josh Miller on the mound after the side session and said Verlander was optimistic about his progress. Verlander reported to camp two weeks behind schedule because of a shoulder issue.

“He walked off the mound feeling really good about his side,” Espada said. “We’ll see how he bounces back tomorrow and see where we go from there.”

• Box score: Astros 5, Mets 2

Espada said it was a “really good day.”

“I saw an upbeat J.V., super positive, really liked the way he felt,” he said. “Even from pitch No. 1 to pitch 60, he felt really good.”

So what’s next? Verlander could soon get back on the mound to face hitters in live batting practice for the first time this season. He would likely need at least two live batting practice sessions before getting into Grapefruit League games, assuming he doesn’t have a setback.

“I think we can start talking about that,” Espada said. “Hopefully, he’s there where we can move forward and start scheduling a live BP.”

The timeline for Verlander to be ready for Opening Day on March 28 against the Yankees remains really tight. Espada isn’t ready to say Verlander won’t be ready to start the season, but even if he doesn’t pitch in the first series against the Yankees, returning in the first week of the regular season would be a positive for the Astros.

“It’s still tight,” Espada said. “Every day that passes that he doesn’t face live BP or live hitters, it works against his ability to be ready for Opening Day. There’s no doubt about it.”

Verlander, who was traded back to the Astros from the Mets last August, experienced a delayed start last year with the Mets as he was placed on the injured list with a right arm injury on the eve of the regular season. He debuted on May 4 and made 16 starts for New York before the Astros acquired him prior to the Trade Deadline.

The Astros will have two key starting pitchers on the injured list to start the season. Luis Garcia underwent Tommy John surgery last May, and Lance McCullers Jr. had surgery to repair his right flexor tendon and remove a bone spur last June. What’s more, starter J.P. France (shoulder inflammation) also has yet to face hitters, though that could come soon.

If Verlander and France aren’t ready to start the season, the Astros could open their defense of the American League West title with a rotation that’s led by Framber Valdez, Cristian Javier, José Urquidy, and Hunter Brown. Espada said Ronel Blanco, Brandon Bielak and top pitching prospect Spencer Arrighetti are among the candidates to fill out the staff.

“Brandon Bielak is a guy that has done it before,” Espada said. “Arrighetti is throwing the ball really well and could be considered for that spot. We do have options, and they’re really good options for us if those guys are not ready for Opening Day.”

Verlander went 7-3 with a 3.31 ERA in 11 regular-season starts (68 innings) in his return to Houston and also made three postseason starts before the club was eliminated by the Rangers in the ALCS.

The three-time Cy Young Award winner is entering the second season of a two-year deal he signed with the Mets last winter. The contract contains a $35 million vesting option for 2025 that is triggered if Verlander throws 140 innings this season. The Mets will pay half of the option if it vests.