PORT ST. LUCIE — Clay Holmes’ buildup as a starter with the Mets extends beyond the physical aspect.

Now at the point in spring training that he’s getting to work multiple times through the batting order, the former reliever is focusing on nuances.

“Doing a little more than just throwing sinkers,” Holmes said Sunday. “I am going to see how I use my pitches, have some type of game plan, read swings, I want to deviate. I am going to experience a little more these next few outings.”

In a 7-6 exhibition victory over the Nationals, Holmes extended to 67 pitches over 3 ²/₃ shutout innings.

He allowed one hit and three walks with eight strikeouts.

With his sinker erratic early, Holmes looked toward other options, including a changeup he has improved this spring.

Holmes threw 16 changeups that induced eight swings.

He received six swings and misses.

“Today I learned that the sinker command wasn’t totally there early and instead of trying to force that, the changeup allowed me to pull back a little bit and I really got to see how it was playing,” Holmes said. “I got a ground ball early with it and some swing-and-miss. Kind of being forced a little bit and have some success with it was good to see.”

Holmes will receive another three starts this spring, with a goal of building up past 90 pitches.

“These next few outings I am looking forward to stretching toward that final pitch count,” Holmes said. “But also just seeing how my stuff plays the second and third time through the lineup.”

Brandon Nimmo expects to resume running on Monday and anticipates a return to the Grapefruit League later in the week.

Nimmo, who received a gel injection in his right knee in recent days, has appeared in only one game this spring.

Justin Hagenman, Kevin Herget, Austin Warren and Jared Young were optioned to minor league camp.

In addition, Rico Garcia, Grant Hartwig, Yacksel Ríos and Brandon Waddell have been reassigned to minor league camp.

The Mets are left with 49 players in camp.