MIAMI -- Edinson Volquez might not make another start before the July 31 non-waiver Trade Deadline.
The Marlins' Opening Day starter and owner of the Majors' lone no-hitter this season will rest at least 7-10 days before attempting to throw off a mound, manager Don Mattingly said on Saturday. Volquez's MRI results on Friday revealed patellar tendinitis in his left knee.
"We're talking probably at least 10 days, so it's gonna be a little bit," Mattingly said, "and then when's he gonna be able to start throwing?"
Volquez was initially scheduled to begin his second half on Sunday versus the Dodgers. Instead, Mattingly will push up rookie Chris O'Grady for the series finale.
O'Grady earned a second start with the club after winning his Major League debut against the Giants on July 8. The left-hander tossed 5 1/3 innings of three-run ball on 81 pitches.
The last time Volquez threw off a mound was his last start on July 5 in St. Louis. He exited after four innings with knee pain and landed on the 10-day disabled list two days later.
Volquez has since thrown, but only to the extent of light tossing in San Francisco and long tossing back home in the Dominican Republic over the All-Star break. He said he's unsure how healthy his knee is because he hasn't tried tossing off a mound.
"It's getting better," Volquez said. "It'll take some time to be 100 percent probably to pitch. But still working on it."
Volquez sustained similar soreness in his knee earlier this season, but he pitched through it. The 34-year-old is 4-8 with a 4.19 ERA in 2017 and said his left knee has given him trouble over the last four seasons.
"I'm getting old," Volquez joked.
With O'Grady starting on Sunday, that leaves right-hander Tom Koehler to open against the Phillies on Monday. Tuesday's starter is still unknown, but it could be reliever Vance Worley.
"Anybody in the organization," Mattingly said regarding Miami's temporary open rotation spot. "It does include Vance, and that's why I say TBD right now."
Patrick Pinak is a reporter for MLB.com based in Miami. This story was not subject to the approval of Major League Baseball or its clubs.