This story was excerpted from Thomas Harding’s Rockies Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.
The three scoreless innings that left-handed Rockies No. 11 prospect Sean Sullivan pitched in his Major League debut -- a start Friday night vs. the Athletics at Las Vegas -- provided a preview of a pitcher whose unusual style can perplex batters.
Sullivan, 23, who left the game because of illness, averaged 87.6 mph on his four-seam fastball. That is well below the Major League average. Yet the Athletics managed two hits and struck out twice, and whiffed at three fastballs and a sweeper changeup.
The idea of Sullivan, called up from Triple-A Albuquerque, missing bats with less-than-elite velocity is not new. The Rockies took him in the second round of the 2023 MLB Draft out of Wake Forest after he struck out a school-record 14.34 batters per nine innings.
Rockies teammates who played with him on the way to the Majors understand what works. Sullivan uses an unusual delivery and elite extension -- he releases the ball 7.4 to 7.6 feet closer to the plate than where he starts on the rubber. That’s some reach for a pitcher who is listed at 6-foot-4.
While his calling card has been busting right-handed hitters inside, on Friday, Sullivan flashed the trait the Rockies wanted to see this season. He has found a changeup and a sweeper on the opposite side of the plate.
“He releases well from an odd angle, so it plays up and gets a lot of swings and misses, where normally you wouldn't expect it to be a swing and miss,” said Braxton Fulford, who caught Sullivan when the two were at Albuquerque. “He's also improved a couple of his pitches, especially the changeup lately, so I think that's really opened up his whole arsenal in the right direction to have big league success.”
Before receiving the call, Sullivan’s results featured wild swings from good to bad (5-3, 5.60 ERA in 11 starts). Fulford believes the up-and-down of his Triple-A time could be a plus.
“Something that might be overlooked is he's level-headed -- not complacent with giving up runs,” Fulford said. “If he gives up runs, he's not folding under the pressure. That's really going to help him at this level,”