Burdi threw a perfect inning against the Twins on Wednesday.
The Rule 5 pickup, who spent one month on Pittsburgh's roster last season, will need to stay with the team an additional two months or be offered back to Minnesota. "He's come in in a good spot. He's been competing. He's been making pitches," manager Clint Hurdle said. "The velocity's playing. The slider's come into play a little bit. He continues to give you things to think about." Burdi has posted a 1.93 ERA in 9.2 spring innings, including a 13:3 K:BB. As a result, there's a good chance he takes the last bullpen spot and pitches in middle relief to start 2019.