Mason Montgomery (or "Monty," as some like to call him) might be a more well-known name to some Rays fans, and to those, I applaud you, good job for being well-informed.
But if you're hearing that name either for the first time or you just don't know much about him, that's fine. That's the Rays. They get seemingly random (to us) pitchers and turn them into productive members of their team all the time.

And now they have Mason Montgomery, a 24-year-old lefty who figures to compete for a spot in the Rays' bullpen for the 2025 season.
Montgomery was selected in the 6th round of the 2021 draft out of Texas Tech, and has made steady progress through his time in the Rays' system, ending up in Triple-A for the first time in 2023 and getting the call for the majors last season for his debut.
2024 was a bit of a rough year for Monty in terms of pure results, as his FIP ballooned to a 5.39 over a tick under 90 innings, but he was dealing with a seeming transition to the bullpen, as he was mostly a starter during his time progressing through the minors.
Every other year he was making appearances entirely as a starter, but last season saw him make only 14 starts compared to 31 games appeared in total.
And that might be intentional, as the Rays could identify Monty's skill set as one best suited for the bullpen instead of as a starter.
Up to this point he's still got that elite, upper-90s fastball to go with a really good slider that graded out as being 27% above average in Stuff+.

But he's failed to develop that change-up into anything useful, as it only posted a 93 in Stuff+ in AAA for the 2024 season and he didn't use it at all during his 9+ innings with the major-league squad.
So that might be reason enough for the Rays to decide that hey, we've got enough starters right now, let's use Montgomery in his most optimal role, letting him air it out in the bullpen and not having to worry about varying his looks too much with more than his 2 great offerings.
Because even though he gave up some hard contact in AAA last year with a 41% hard-hit rate allowed, he also still posted a 93rd percentile whiff rate and a 31.3 chase rate, both excellent marks.
So the Rays could be using Montgomery quite a bit in the majors this season, especially with the usual and unfortunate ration of pitching injuries that hit every team.
The big question is just how he'll be deployed; will it be in that familiar starting role as a potential multi-inning opener, or will he be used as a late-inning, high-leverage reliever, or a bit of both?
With the Rays, it's hard to rule out anything.