NEW YORK (AP) — Arizona Diamondbacks ace Zac Gallen was placed on the 15-day injured list Friday because of a strained right hamstring.

The defending National League champions recalled right-hander Slade Cecconi from Triple-A Reno before the second game of a four-game series against the New York Mets.

Gallen was removed six pitches into Thursday night’s start at Citi Field. He went back to Arizona on Friday to undergo an MRI and get evaluated by team doctors.

The 28-year-old right-hander is 5-4 with a 3.12 ERA in 11 starts. He finished in the top five of NL Cy Young Award voting each of the past two years, including third last season when he went 17-9 with a 3.47 ERA in 210 innings and made his first All-Star team.

Gallen’s injury is the latest blow to a slumping Diamondbacks team that had lost four straight to fall six games under .500 at 25-31, equaling a season low. Arizona already was missing starters Merrill Kelly, sidelined since April 15 by a strained right shoulder, and Eduardo Rodriguez, who hasn’t pitched this season because of a strained left shoulder after signing an $80 million, four-year contract as a free agent.