The 24-year-old has been less than impressive so far in his young career as he has a 3-8 record, 8.45 ERA, 2.15 WHIP, 7.26 FIP, 39 strikeouts, and 41 walks in 54 1/3 MLB innings (10 starts).
Most of his appearances came in 2017 as he only made four (one start) with the team last year. He managed to pitch even worse in those appearances than he did in 2017 (7.88 ERA) as he allowed 13 runs (nine earned) in 6 1/3 innings to give himself a 12.79 ERA for the 2018 season.
However, what allowed Flexen to even reach the majors in the first place was the promise he displayed while pitching for Single-A St. Lucie and Double-A Binghamton in 2017.
Between the two levels, the California native went 6-1 with a 1.76 ERA, 0.81 WHIP, and 63 strikeouts as compared to 10 walks in 61 1/3 innings (10 starts, two complete games).
As of now, Flexen is currently sitting on the outside looking in as there is currently no opening in the rotation for him and he is unlikely to make the team as a reliever given the fact that four spots are locked down (Seth Lugo, Robert Gsellman, Jeurys Familia, and Edwin Diaz) and the still needs to add at least one left-hander whether that be from within or from the outside.
Even if the team goes with one lefty and that pitcher is Daniel Zamora, that would leave only two spots open for any combination of Drew Smith (very likely to reclaim a spot), Tyler Bashlor, Jacob Rhame, Tim Peterson, Paul Sewald, Bobby Wahl, and Eric Hanhold.
That being said, Flexen has a strong chance of getting a shot in the rotation at some point this season given the fact the team does not have that much depth starting pitching wise past their top-five. Flexen will be serving as insurance along with Corey Oswalt, Rule 5 Draft Pick Kyle Dowdy, and the Zach Lee who was signed to a minor league deal yesterday.
While Flexen has yet to impress in the majors, his motivation to make the team coupled with his youth still make him worth keeping an eye on in 2019.