MIAMI -- After missing almost all of last season due to injury, Marlins right fielder Garrett Cooper once again is on the 10-day injured list.

This time Cooper is expected to miss at least a few weeks with a left calf strain, incurred on Friday night and aggravated in a pinch-hit appearance in Saturday’s 7-3 victory over the Rockies at Marlins Park.

Replacing Cooper on the rosters is Peter O’Brien, who was recalled from Triple-A New Orleans and started in right field on Sunday in the series finale.

“It’s definitely frustrating,” Cooper said on Sunday morning. “After a long year of rehab, to come back and get hurt again. It’s not what I want. I’ll take the rehab, day-by-day.”

A year ago, Cooper was limited to just 14 games due to a right wrist injury that required surgery.

The Marlins had been hopeful Cooper was dealing with just a cramp and would be back in the lineup on Sunday. That changed after the 28-year-old pinch-hit in the sixth inning when he popped out and felt some discomfort in his calf coming out of the box.

“After the pinch-hit, I tried to run on it, and it felt like something pulled,” Cooper said. “So, it will be a few weeks before I can start to get back to baseball stuff.”

Cooper won a spot on the Opening Day roster over O’Brien in what the organization called its toughest roster decision.

O’Brien turned heads in the organization as a September callup in 2018, batting .273 with four home runs and 10 RBIs in the final month.

In Spring Training, Cooper, despite missing substantial time a year ago, showed he was healthy, and he made the club after hitting .395 in Grapefruit League play. He is 0-for-7 on the season.

O’Brien, meanwhile, hit .220/.353/.390 with one home run, four doubles and 11 RBIs in the spring. But in March, the power-hitting 28-year-old picked things up, hitting .300/.450/.533 with one home run, 11 RBIs. What set him back was he was 0-for-11 in February.

“That was probably our tightest one, with Pete,” manager Don Mattingly said. “As we talked about it to our guys in Spring Training, guys fight to make the Opening Day roster. One of the things we talked about was, ‘If you get sent down, make sure you have a good attitude, and go to work. You never know what’s going to happen. It could be 10 days and you’re back.'”

O’Brien, actually, never left the Marlins’ Spring Training complex in Jupiter, Fla. That’s because the Triple-A season doesn’t start until Thursday, and the club has still been training in South Florida.

So O’Brien was able to travel to Miami in time to be in right field Sunday.

“It’s not the first time I’ve been through that in my career,” O’Brien said. “As you know, baseball is a game of ups and downs. You’ve got to stay ready. You’ve got to stay available. You’ve got to be ready to go.”