Jason Vargas has one more hurdle to clear before joining the Mets rotation.

The Mets lefty is expected to pitch in a minor league rehab game Sunday in his first true test since undergoing surgery last month to remove the hamate bone in his non-throwing hand.

Vargas pitched from behind a screen Tuesday in an intrasquad scrimmage in Port St. Lucie, Fla., but wasn’t allowed to catch the ball. In six hitless innings, he struck out 12 batters.

“He had great command and was hitting all his spots,” manager Mickey Callaway said before the Mets’ 5-2 loss to the Nationals.

If Vargas appears ready following his minor league start, he could be inserted into the rotation in San Diego, where the Mets will play three games beginning April 27. That would leave Callaway with a decision on potentially removing a starter from the rotation, with Matt Harvey, Zack Wheeler and Steven Matz as the candidates.

Harvey has struggled in his last two starts and would seem the most vulnerable, but Wheeler — who allowed three runs in six innings in Tuesday’s loss — is still trying to prove he belongs after receiving a demotion to Triple-A Las Vegas late in spring training. Matz has pitched respectably in two starts.

As part of the Mets’ Youth Enrichment Programs impacting kids’ lives through sport and mentorship, Wilmer Flores played host to about 15 foster children and their families from Brooklyn-based El Puente in a pregame Tuesday meeting sponsored by Konica Minolta.

“From the first moment, I loved it so we decided to keep doing it this year,” Flores said. “We give them tickets to the game so they have a good time and we get them into the cage and take some pictures and just hang out.More importantly, they have a different day.”

— Additional reporting by Fred Kerber