The lanky right-hander, a Clemson University commit, posted a 0.92 ERA and struck out 82 batters in 54 innings this spring, according to the Tampa Bay Times. MacGregor's velocity reportedly ticked up as the year went on, jumping from the high 80s to the low 90s.
"Travis is definitely coming into his own a little bit," Pirates scouting director Joe DelliCarri said. "Definitely has shown a nice progression through last fall and then this spring. We continue to see improvements over a timeline in Travis, for sure."
The newspaper also reported that MacGregor worked out for the Rangers, Blue Jays, Marlins, Yankees, Astros and Mets in addition to the Pirates.
"It's been crazy," MacGregor told the Tampa Bay Times. "This is a very new experience for me. But it's been exciting."
MacGregor was the Pirates' third and final selection on Day 1 of the Draft. They took Wake Forest University infielder Will Craig in the first round and California high school left-hander Nick Lodolo with the 41st overall pick.
Like Lodolo, the 6-foot-3, 180-pound MacGregor, is relatively unrefined but possesses many of the traits the Pirates look for in young pitchers. That's to be expected in the Draft, of course, and Pittsburgh has faith in its ability to develop pitchers as they progress through the Minor League system.
"They're guys that we believe will grow and develop, have arm speed, have athleticism, have pitches that we see now but can project on into the future," general manager Neal Huntington said. "We're very pleased with their projected path."
Huntington noted that the Draft's bonus rules, with assigned slot values and an overall bonus pool value given to each team, can affect how teams pursue high school players. The 68th pick, for instance, has an assigned bonus value of $948,900.
"There's no question that the new system makes it more challenging to take a high school player later in the draft and pay him what you think he's worth," Huntington said. "If you think a pitcher's worth the second-round figure, you essentially need to take him in the second or third round. It's much harder to take him in the eighth or ninth round, as we used to our first four years here.
"The system does structure that, as you're taking guys that are looking for certain amounts of dollars, you've got to be aware of where you're selecting them in the Draft."
The Draft continues on Friday with Rounds 3-10. The MLB.com preview show begins at 12:30 p.m. ET, with exclusive coverage of Rounds 3-10 beginning at 1 p.m. ET.