Jon Niese walked off the mound at Tradition Field ready to go. The lefty threw 4-/3 scoreless innings against the Astros, more than expected, and walked off proclaiming himself ready for his Opening Day start Monday against the Padres at Citi Field.

“I felt good. Tonight it felt like I had everything going, especially the curveball, for the most part could control, throw it for a strike, or in the dirt when I wanted to,” Niese said. “Overall, I felt good. . . . I am excited, real excited and ready to get it going.”

Niese struck out seven, walked two and scattered two hits in the Mets’ 6-2 win Wednesday night, his last start of spring training. While the 26-year-old was tabbed Opening Day starter last week, the Mets announced the rest of their starting rotation for the first two series of the season.

Niese will open the season against the Padres’ Edinson Volquez, followed by righthanders Matt Harvey and Dillon Gee against San Diego. Righty Jeremy Hefner will open the series against the Marlins. With a day off in the first series, Niese will pitch on normal rest in the second game of the Marlin series, followed by righthander Shaun Marcum.

Hefner, who had a sleeve on his right elbow after getting hit by a come-backer on Tuesday, said he felt better. Hefner is shut down from baseball activities for a few days, but would like to throw again as soon as Friday.

Marcum, who suffered neck pain in a bullpen session on Monday, said he would be ready to take his turn in the rotation.