CLEARWATER, Fla. - The category: Phillies Relievers.

The answer: After being called up from Triple A Lehigh Valley in late May, this homegrown righthander finished the season in dominant fashion, posting a 1.89 ERA and allowing just two home runs while averaging a strikeout per inning in 50 appearances.

The question: Who is Justin De Fratus?

If you don't know, pay attention. He might not hit 100 mph like Ken Giles and Jake Diekman, and he might not save games and grab, um, headlines like Jonathan Papelbon, but De Fratus is far from a third or fourth wheel in the back of the Phillies' bullpen. In fact, with the offseason departure of Antonio Bastardo, he is expected to move into an even more prominent role in front of the club's eighth- and ninth-inning triumvirate.

That's a drastically different situation than the 27-year-old De Fratus seemed headed toward at this time last year, when a sluggish fastball and a string of rocky outings convinced the Phillies to send him down to Triple A Lehigh Valley. De Fratus was coming off a breakout 2013 when he spent the last 5 1/2 months on the big-league roster, posting a 3.86 ERA in 58 appearances. But when the 2014 season began something looked off. His fastball lacked its usual life, and opposing hitters feasted on it, tagging him for a pair of home runs and four earned runs while striking out just twice in his first four appearances. When Ryne Sandberg informed De Fratus of his demotion, the manager wasn't sure what, exactly, the future had in store.

"I didn't know how he'd come back," Sandberg said. "But he went down there with a plan to work on things and he did - he regained his fastball, which he still has."

Turns out, all De Fratus needed was a little more time to build up arm strength. A 2-week bout with the flu during spring training had drained him of strength and interrupted his usual progression. When he returned at the end of May, he was a different pitcher, holding opponents scoreless in each of his first 16 outings. During that stretch, he struck out 18, walked four, and allowed just three extra-base hits, none of them home runs, in 17 innings. By the end of the year, he had career bests in innings (52 2/3), ERA (2.39), strikeouts-per-nine (8.4) and walks-per-nine (2.1). His 4.08 strikeout-to-walk ratio ranked 16th in the National League out of 64 righthanded relievers (Giles was third at 5.82 and Papelbon 12th at 4.08).

"I had to build some strength back up," De Fratus said. "I was healthy when the season started, but I lost that prep time. I didn't want to go to Triple A, but I guess it was needed. I needed this time just to get the work back."

Nearly 2 weeks into Grapefruit League play, the Phillies' bullpen remains the only area of the team to inspire much confidence. Yesterday, lefty Elvis Araujo pitched his third scoreless inning of the spring. Papelbon also logged a scoreless frame. Giles has walked three and struck out one while allowing one run in two innings. Diekman has two strikeouts, a walk and a run allowed in two innings.

De Fratus, meanwhile, has pitched two scoreless innings, allowing two hits and striking out one. He looks strong and healthy - that's partially attributable the avoidance of illness, but also a renewed focus on conditioning in the offseason.

"I think he's learned a little bit about himself being around some older pitchers and being in the big leagues a whole year," Sandberg said. "I think that went a long way with his offseason plan for being ready."

The key to surviving this season as a Phillies fan will be ignoring the score and focusing on the process. The evolution of De Fratus' role will be one of those processes. Sandberg would like him to get to a point where he is capable of pitching multiple innings, a job that has gained renewed importance with the likely absence of Cliff Lee.

"Up till now he's been a situational guy, getting out of a jam as a righthanded reliever," Sandberg said. "For him to add some durability and be able to go two innings would be the next step."

Who is De Fratus? This year we will continue to find out.

On Twitter: @ByDavidMurphy
Blog: ph.ly/HighCheese