The outfielder has stepped up, batting .405 with five home runs and 15 RBIs in 30 games. In the four-game series at Milwaukee, he was 7-for-16 with three home runs and six RBIs. He collected two more hits in Friday's 3-2 win over the Cardinals.
Ruggiano joined Miami in a Minor League deal with the Astros on May 26. A day later he was in the big leagues. Now, it's going to be tough to keep him out of the lineup.
"In the Minor Leagues, you've got to be mentally tough," Ruggiano said. "I was thinking about life after baseball while I was in the Minors quite a bit. You get stuck in that Minor League system and you feel like there is no light at the end of the tunnel.
"Eventually, you're not going to play Minor League ball forever."
Ruggiano, whose new Twitter handle is @JustinRuggiano, has been one of Miami's biggest surprises, because it appears he literally came out of nowhere.
He came up through the Rays' system, and he made his big league debut in 2007, appearing in seven games. In 2008, he saw action in 45 games. From there, he was in the Minor Leagues.
Ruggiano resurfaced with Tampa Bay for 46 games in 2011.
In the offseason, he was left off the Rays' roster, and the Marlins tried to sign him to a Minor League deal. But the outfielder opted to hook up with the Astros, and he opened the season at their Triple-A affiliate in Oklahoma City.
"He was on our radar in the offseason," Marlins general manager Michael Hill said. "Our goal from Day 1 in the offseason was to bring in right-handed bat competition. The makeup of our roster, we wanted a right-handed complement."
The Marlins ended up signing Aaron Rowand and Austin Kearns to Minor League deals. Rowand was released at the end of Spring Training. Kearns made the roster, and he's still with the club.
Ruggiano is just trying to make the most of his opportunity.
"I've always thought that if I was given a chance and an extended look, I'd eventually perform," he said. "Sometimes it takes a while to get comfortable, and to adapt."