BALTIMORE -- After spending the spring rehabbing from a left oblique strain, right-hander Brett Graves finally got his first big league callup with the Marlins, who reinstated him from the 60-day disabled list on Friday ahead of a 2-0 win over the Orioles.
A Rule 5 Draft selection from the Athletics' organization, the 25-year-old Graves comes up after exhausting most of his 30-day rehab assignment, in which he went 1-2 with a 5.59 ERA in seven appearances (three starts) for Class A Advanced Jupiter and Double-A Jacksonville.
Graves last threw for Double-A on Tuesday, logging two scoreless innings with one strikeout.
"His rehab was coming to an end, so we were going to have to do something," Mattingly said. "The timing of it just means that we get an extra guy for a day or a couple of days."
In a season where the Marlins are evaluating many young players, Graves will get a chance pitching out of the bullpen after spending most of his career starting. He is a candidate to throw multiple innings. Graves was a third-round Draft pick by Oakland in 2014, and he has logged 381 1/3 Minor League innings, with 270 strikeouts and 120 walks.
Miami transferred southpaw Chris O'Grady (left shoulder sprain) to the 60-day DL to make room for Graves on the 40-man roster.
The Marlins also recalled righty Merandy Gonzalez from Double-A Jacksonville, needing bullpen length after a 16-inning, 6-3 loss to the Giants on Thursday.
The 22-year-old Gonzalez returns just over a month after his first big league stint, in which he posted a respectable 2-0 record and 4.85 ERA in six relief appearances. Gonzalez, who compiled a 3.43 ERA in five starts for the Jumbo Shrimp, ranks as Miami's No. 13 prospect, according to MLB Pipeline.

"It was really more about length and having innings out there," Mattingly said. "One of the things with Merandy, we want him to continue to develop. We like him as a starter, but we know he's been out there a little bit. He did a nice job I thought when he was here."
To make room, Miami optioned right-hander Ben Meyer to Triple-A New Orleans. The Marlins also placed lefty starter Caleb Smith on the bereavement list to attend a funeral.