PHILADELPHIA – The Mets’ starting rotation depth could be tested yet again.

Taijuan Walker left his Monday start against the Phillies after only two innings because of right shoulder irritation, the team announced. The team had been monitoring Walker after he departed his final spring training start with right knee discomfort.

David Peterson replaced Walker for the third inning.

The Mets are already without Jacob deGrom, who began the season on the injured list with a stress reaction on his right shoulder. The Mets ace likely won’t rejoin the rotation before late May at the earliest.

Tylor Megill has replaced deGrom in the rotation. The lefty Peterson would be a candidate for a spot if Walker needs an IL stint.