You never know when a team might stumble into a hidden gem prospect, either through the late rounds of an MLB Draft, the international signing period, or an undrafted free agent.
And the Chicago White Sox seem to have found a bullpen arm who could quickly become a name to watch.
Left-handed pitcher Grant Cleavinger signed with the White Sox as an undrafted free agent after the 2026 MLB Draft out of Nebraska. And the start to his professional career includes numbers that are hard to believe.
Cleavinger, 22, is the younger brother of longtime MLB reliever Garrett Cleavinger, who is currently in the bullpen for the Tampa Bay Rays and has posted a 3.28 ERA over 233 career MLB appearances. Baseball bloodlines are usually a goos sign, but during his college career at Nebraska, Cleavinger could never really figure out how to harness his swing-and-miss stuff.
He played three years for the Cornhuskers after transferring in from Tulane. Over the course of his collegiate career, he posted a 7.83 ERA, largely due to 42 walks being allowed over 43.2 innings pitched.
Still, 69 strikeouts over those 43.2 innings was good for 14.2 K/9. Combine that with the really promising spin rates on his fastball, and it was enough to intrigue the White Sox and convince them to give Cleavinger a chance as an undrafted free agent.
Whatever the White Sox saw, and whatever adjustments they made before sending Cleavinger on assignment to Low-A Kannapolis, it seems to be working, because the start of his professional career couldn't be more dominant.
Over his first nine appearances in the White Sox organization, Cleavinger has completed 10 innings while allowing just one run, one walk, and two hits. That's good for a 0.30 WHIP and a 0.90 ERA. He has also recorded an unbelievable 24 strikeouts in those 10 innings.
Cleavinger has faced 33 batters. He has retired 30 of them. And he has struck out 24 of them. It truly doesn't get much better than that. The White Sox found themselves a 22-year-old, six-foot-five left-handed relief pitcher who's making professional baseball look like Little League.
Cleavinger's undrafted status guarantees you won't find him on any top prospect lists for the time being. But he's definitely a name to watch for White Sox fans, both now and in the future.
He’s been so good at Kannapolis that Cleavinger is making a strong case for an early promotion to Winston-Salem at the start of his professional career. And, as is the case with many college relief pitchers, rapidly ascending through the ranks of minor league baseball is not uncommon.
Any undrafted free agent who reaches the MLB level is a player development win for an organization. So it’s not at all insignificant that the White Sox might have their hands on a high-leverage left-handed relief arm, thanks to some tremendous scouting and quick adjustments.
Cleavinger still has a long way to go, and it’s far too early to know whether this dominant stretch will translate as he moves up the minor league ladder. But for an organization always looking for ways to add talent, finding a pitcher with this kind of swing-and-miss ability without even using a draft pick could prove to be a significant development win for the White Sox.