Shawn Kelley is back on the disabled list. (AP Photo/John Bazemore)

NEW YORK — The Nationals’ bullpen shuffling continued Sunday, when the club placed Shawn Kelley on the 10-day disabled list with a right trapezius strain Sunday and recalled A.J. Cole from Class AAA Syracuse to take his spot on the roster.

Kelley said he began feeling tightness around his neck late in his outing against the Mets Friday night, which began with him allowing a leadoff home run to Jay Bruce. He said he’s not “100 percent sure what it is” and doesn’t know the extent of the severity, but he couldn’t throw. It’s the latest twist in a frustrating season for the 33-year-old Kelley, who was on the disabled list last month with a lower back strain and has struggled when healthy.

“It’s unfortunate,” Kelley said. “But things happen and you have to deal with them, I guess. It’s not ideal.”

The right-hander has a 7.00 ERA and surrendered nine home runs in 18 innings. The 4.5 home run rate is the third-highest in baseball among relievers that have thrown at least 10 innings — only the Phillies’ Adam Morgan and teammate Joe Blanton have allowed more home runs per nine innings.

Cole returns to Washington for the second time this season. The right-hander made one start in his previous stint, holding the Phillies to one run over six innings. He’s posted a 5.68 ERA in 10 outings for Syracuse, though.

Cole joins the Nationals as they seek a four-game sweep of the Mets and their seventh straight win at Citi Field. It’ll be Joe Ross versus Jacob deGrom.

As for potential future  bullpen help, the Nationals and third-round draft pick Nick Raquet finalized a deal Saturday night, according to a person with knowledge of the situation. The left-hander out of William & Mary agreed to a signing bonus less than his $522,300 slot value as the 103rd selection and will have his physical in D.C. Sunday.

NATIONALS (42-26)
Trea Turner SS
Brian Goodwin LF
Bryce Harper RF
Ryan Zimmerman 1B
Daniel Murphy 1B
Anthony Rendon 3B
Matt Wieters C
Michael A. Taylor C
Joe Ross RHP

METS (30-37)
Michael Conforto CF
Jose Reyes SS
Jay Bruce RF
Wilmer Flores 2B
Lucas Duda 1B
Curtis Granderson LF
T.J. Rivera 3B
Travis d’Arnaud
Jacob deGrom RHP