This year, Slowey finds himself back with the Marlins as a non-roster candidate trying to win a spot among a group of promising young pitching prospects.
It wasn't a given Slowey would return.
After the 2013 season, he declined a Minor League assignment and became a free agent. He then weighed all of his options.
On Jan. 8, the Marlins announced the right-hander had agreed to rejoin the organization.
"There are always opportunities out there," Slowey said. "But for me, there is nothing better than a known commodity. Not just knowing the players in this clubhouse but the front office and the staff."
The 29-year-old also was a teammate of Marlins manager Mike Redmond during his tenure with the Twins.
"I know they're going to be honest with me, and shoot straight with me, and tell me if there is an opportunity," Slowey said. "If there is, great. If there is not, we'll find somewhere else to go."
Slowey went 3-6 with a 4.11 ERA in 20 games -- 14 starts -- last year.
After logging 92 innings, his season ended in late July due to right forearm discomfort.
Slowey was examined by Dr. James Andrews, who claimed the pitcher was bothered by a flexor strain. Six weeks of not throwing was recommended.
"By the end of last year, before we left, I had thrown a couple of bullpens," he said. "I felt confident going into the offseason. Then I started up with bullpens at the middle of November to the end of November."
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter