PHOENIX — Arizona pitcher Brandon Webb has had another setback with his ailing right shoulder, raising the possibility the Diamondbacks ace may need surgery.

Webb missed the team’s trip to New York and instead will visit Dr. Keith Meister of the Texas Rangers in Dallas, Diamondbacks general manager Josh Byrnes said Thursday.

Webb has consulted numerous doctors but has been unable to relieve stiffness and soreness in the shoulder. The 2006 NL Cy Young Award winner has not pitched since opening day and has been limited to throwing off flat ground.

‘‘He’s not probably making the progress we were hoping for, so I think we have to make an assessment about what to do next,’’ Byrnes told reporters in a conference call. ‘‘He’s worked hard. It’s just when it comes to throwing, it just hasn’t been much different recently than it was going back to late May or June.’’

Byrnes declined to address the possibility that Webb might require surgery, saying he wanted to be cautious.

Earlier this month, after meeting with team doctors and three other physicians, Webb rejected surgery and opted for a more conservative approach.