Instead, Jannis opted to switch from being a conventional pitcher to a knuckleballer.
"It's just a decision I made after I got released by the Rays after my second year in pro ball," Jannis said. "I went into independent baseball and just made the transition. It's been a long process. I'm still learning to throw it, learning to throw it for strikes. It's just every day learning something new with the pitch."
Fine-tuning the knuckleball is not the only transition Jannis has had to make. The Rays used Jannis primarily out of the bullpen while the Mets have been using him as a starter.
However, he has navigated that adjustment well. In the Arizona Fall League, facing more advanced hitters, Jannis has a 1.88 ERA in 24 innings across five starts.
"It's going pretty well," Jannis said of his stint in the AFL. "I've been working on a few mechanical changes and every time out I feel a little more comfortable. It's going well."
But there were years of adversity before his dominant Fall League showing, going all the way back to Jannis' college days.
The right-hander faced challenges immediately in his collegiate career. When he showed up to Cal State Bakersfield in 2009, there was no guarantee the team would actually play baseball.
In fact, there was no field. The players, Jannis included, had to build it themselves.
"We built the field from the ground up, literally," Jannis said. "We laid the grass on the field, the whole team. They didn't hire any workers, they had the team do it. It was a big team bonding type of thing. It was a great experience."
After building the field, Jannis was named the Opening Day starter and threw the first pitch in Cal State Bakersfield history -- a fastball.
Jannis' teammates encouraged him to throw the knuckler that day, but he opted against it. He's always had it in his repertoire, but never threw it in games.
That is, until he found himself in independent leagues.
"Growing up, I always fooled around with it on the side so it wasn't a huge change for me, and I threw it off and on in summer leagues and stuff like that, but nothing serious," Jannis said. "It's just something you have to commit to, and probably the last two years is when I really committed to it and it's paid off so far."
It certainly has paid off and it's a big reason why Jannis was given an opportunity with the Mets, the same organization that fellow knuckleball pitcher R.A. Dickey revitalized his career with.
Jannis, similar to Dickey, likes to throw his knuckler harder than most. Jannis keeps his knuckleball in the upper 70s and low 80s, but says it has topped out at 84 mph.
The 27-year-old spent parts of the past four seasons in independent leagues, but after starting the 2015 campaign with a 1.18 ERA in 83 2/3 innings for the Long Island Ducks, Jannis signed with the Mets in July.
Once with the Mets, Jannis split his time between Class A Advanced St. Lucie and Double-A Binghamton, where he went a combined 2-3 with a 3.55 ERA in 11 games (10 starts).
Admittedly, Jannis considered giving up on baseball during his struggles, but could never bring himself to do it.
"I love the competition, I love to play," he said. "It's what I've wanted to do my whole life so I've stuck with it. It's been a long few years in independent ball."
Life in the independent leagues wasn't easy, but Jannis' pitches still had life and as long as he could compete at a high level, he was intent on pursuing his dream.
"I was having success. I told myself that as long as I was still having success and getting guys out, I was going to give myself a shot," Jannis said. "With the knuckleball there's no age limit, so I knew I always had a shot."