WASHINGTON, D.C. -- Jose Fernandez is on Miami's Opening Day roster after all.

An unexpected series of events led to the Marlins reversing course on Fernandez, who now steps into a big league rotation without pitching above Class A.

"It is crazy," Fernandez said on Sunday morning before the Marlins worked out at Nationals Park. "I'm happy to be here. It's work I've worked for my whole life."

Marlins owner Jeffrey Loria personally told Fernandez on Friday that he would be joining the club for Monday's Opening Day at Washington.

The 20-year-old is scheduled to make his big league debut on April 7 with a start against the Mets at Citi Field.

The decision to promote their top prospect was made largely because of injuries to the rotation. The startling transaction came on arguably the wildest day before a season opener in franchise history.

Fernandez, ranked seventh on MLB.com's Top 100 Prospects List, has thrown a total of 134 career Minor League innings. Born in Cuba and raised in Tampa, Fla., the right-hander with the 96-mph fastball has dominated. He is 14-1 with a 1.75 ERA in his Minor League career, with 158 strikeouts and 34 walks.

Fernandez was Miami's No. 1 Draft pick in 2011. He was in big league camp, but was sent down a few weeks ago and was getting ready to pitch for Double-A Jacksonville. According to Baseball Prospectus, Fernandez could become just the third 20-year-old pitcher in the last 25 years to throw 100 innings in a season with no experience above Class A, joining Rick Porcello and Jeremy Bonderman.

His services were called upon because Nathan Eovaldi and Henderson Alvarez were placed on the disabled list on Sunday, due to right shoulder inflammation.

Alvarez is on the DL, retroactive to March 27, while Eovaldi's stint is backdated to March 24.

The injuries have forced the Marlins to scramble their rotation. Eovaldi was initially set to pitch on Wednesday at Washington, while Alvarez was lined up to go on Friday at New York.

The Marlins broke Spring Training in Jupiter, Fla., on Thursday, and Fernandez was in the dugout on Saturday for Miami's exhibition against Triple-A New Orleans at New Orleans.

Now, the revised rotation has Ricky Nolasco going on Opening Day on Monday. Kevin Slowey, initially scheduled to be the fifth starter, will pitch on Wednesday against the Nationals and Wade LeBlanc will close out the series on Thursday.

Miami on Sunday also recalled right-hander Alex Sanabia, who will start against the Mets on Friday. Nolasco will get the call on Saturday, and Fernandez will close out the road trip.

Marlins president of baseball operations Larry Beinfest said Fernandez will be on an innings and pitch-count limit this year. The right-hander will throw between 150-170 innings. Beinfest didn't give the specifics on pitch count.

"This has been tugging at us a little bit," Beinfest said. "We watched him in big league camp. We watched him last year. We watched him go down to the Minor Leagues. He's been just outstanding."

Fernandez accepts whatever limits the team places on him.

"They have a plan for me, and I know whatever plan they have for me, is for the best," Fernandez said.

Marlins manager Mike Redmond said the focus will be more on the innings than the pitch limit.

"We were excited to get a chance to watch him throughout the course of Spring Training," Redmond said. "Now, we're excited to have the chance to see him pitch in the big leagues.

"The innings limit [is] 150-170. We talked about it. That's just part of him. That's where we want to stay, and that's what we're going to do."

Regarding Eovaldi and Alvarez, the Marlins are hopeful they will be back toward the end of April.

"For whatever reason, they got tendinitis -- some mild inflammation in there," Beinfest said. "I'm not sure that it's pain for either one of them. It's just tightness. They're both young guys. We've got a long way to go."

Had Eovaldi and Alvarez remained healthy, Fernandez would have started off at Jacksonville. But still, it was going to be only a matter of time before his promotion.

In his last three Double-A Spring Training outings, the right-hander threw 12 scoreless innings -- striking out 19, while scattering just three hits.

"That's what I came to the United States for, to play in the big leagues," Fernandez said. "I'm going to try to enjoy every bit of it."

The Marlins wrestled with a number of issues regarding the rotation and Fernandez. It's unusual to have such an inexperienced and touted prospect break camp with the big league club.

By being with the team from Day 1, that means his MLB service-time clock starts right away, meaning he can reach arbitration and free agency quicker.

"When we got the word that Alvarez was not going to make it to Opening Day, we talked about what we were going to fill in [with]," Beinfest said. "Jose was always there. He was just so good down [in the Minors]. We went through a lot of time, from the top down, starting with Jeffrey, all the way to our Minor League people. The consensus was, this kid is ready to handle it here. He can pitch here. We had already put in place an innings goal for him."

Entering Spring Training, the Marlins were projecting the rotation would include Nolasco, Eovaldi, Alvarez and Jacob Turner.

But Turner struggled in camp, and he is starting off at New Orleans. So basically, three-fifths of the expected rotation isn't with the club on Opening Day.

"So we're going to ask some people to step in and step up," Beinfest said.

The Marlins announced on Sunday they have selected the contracts of seven players -- Fernandez, Austin Kearns, Casey Kotchman, Chad Qualls, Slowey, Chris Valaika and John Maine.

Because Miami's 40-man roster had been at 40, the team needed to clear up space. In doing so, the Marlins placed Logan Morrison (right knee), Alfredo Silverio (right elbow) and Jose Ceda (right elbow) on the 60-day disabled list.

"We've never seen anything like this, in terms of selecting seven guys," Beinfest said. "It's not even close. You usually get a couple of guys. The number on the DL is high. The number designated for assignment is probably a record with what I have been involved with. In the last 72 hours, the number of different plans that we had in regards to pitching, I think, will be up there as well."

First baseman Joe Mahoney (oblique) and catcher Jeff Mathis (broken collarbone) were placed on the 15-day disabled list.

The club also designated infielder Zack Cox, outfielder Gorkys Hernandez, lefty reliever Scott Maine and right-hander Evan Reed for assignment.

Beinfest acknowledged calling up Fernandez was a bold move. But it was a decision the club felt needed to be made.

"We understand we can potentially have some criticism, saying, 'The guy hasn't pitched in Double-A,' this and that. And this guy is a valuable asset," Beinfest said. "I think we understand all those things, and we went through them. But they're all different. Some guys are going to be ready at 24. Some guys are going to be ready at 20. That's just the way it goes."