The 27-year-old right-hander from Venezuela remains intriguing because of his overpowering fastball. But he's had issues finding the strike zone.
At Triple-A New Orleans, Rodriguez mixed dominance with occasional wild streaks in 19 1/3 innings. His top fastball reading with the Zephyrs was 101 mph, and he struck out a whopping 37 in 19 1/3 innings. But he also walked 23.
Still, Rodriguez showed enough to prompt the Marlins to select his contract on Sunday morning. Rodriguez fills the roster spot vacated when Carlos Marmol was designated for assignment.
"We think the time Rodriguez spent in the Minor Leagues, we got a little more consistency," president of baseball operations Michael Hill said. "We all saw the stuff, but we also saw it could be a little inconsistent. But he's coming off some solid outings in a row. We felt it was time to take a look."
Rodriguez threw three innings on Tuesday, striking out four with no walks. His last appearance before that was on May 3, and he struck out five and walked four in two innings.
Rodriguez last appeared in the big leagues in 2013 with the Cubs and Nationals. In 22 games, he walked 20 in 22 innings and struck out 12.
Rodriguez does have 148 games of MLB experience, and he's struck out 150 and walked 102 in 148 2/3 innings.
Entering the season, the Marlins were hopeful Marmol could emerge in a setup role. He was part of the plan to cover the seventh and eighth innings. But he struggled with an 8.10 ERA in 13 1/3 innings, and after he gave up four runs in the sixth inning to the Padres on Saturday night, he became expendable.
"We felt like we did a pretty thorough job following him through winter ball," Hill said. "We saw like every winter ball outing. His delivery had calmed down. His lines were more on line, and everything was working at the plate. We saw that early in Spring Training. I don't know if the competition got to him, but he reverted back to the same guy."
The fact Marmol's mechanics were again off prompted the club to make the move to part ways.
"It's unfortunate because he's a great guy," Hill said. "I thought it was a good mix, makeup-wise for us. But you've got to do the job."
Rodriguez gets his chance to contribute now. He gives the bullpen another power arm. Rodriguez and Carter Capps each can routinely reach 100 mph in velocity. If they can throw enough strikes, the bullpen will have two big weapons.
The Marlins are checking the market for available relief help. They need additional options to take the pressure off A.J. Ramos and Mike Dunn. Ramos and closer Steve Cishek each have logged 15 innings, and Dunn is at 14 1/3 innings.
A few days ago, the Marlins signed Alex Sanabia to a Minor League contract. Sanabia reports to Jupiter, Fla., on Monday, and when he is game ready, he will head to Triple-A New Orleans.
Sanabia rejoins the Marlins' organization after he was released by Arizona. He provides a long-relief option with big league experience.
"We're trying to find the best mix," Hill said. "We've always found a way."