The latest Gillaspie is Casey, who followed his brother to Wichita State and became the third All-American in the family this season. He's also the best prospect in a deep crop of first basemen this year, a near-lock to go in the first round.
"This is my 36th year here, and I don't think it's crazy to say he's the best hitter we've had here," said Shockers assistant coach Brent Kemnitz. "Obviously we've had guys like Joe Carter and Phil Stephenson and Russ Morman in the early years, then Casey Blake and Pat Magness, and more recently Conor and Andy Dirks. That's a lot of guys who've been great here. But when you talk about the year Casey has had this year with the toned-down bats, he might be the best."
Entering the NCAA Division I playoffs -- which Wichita State didn't make -- Gillaspie led the nation in walks (58 in 59 games), ranked second in on-base percentage (.520) and stood fifth in home runs (15) and slugging (.682). He batted .389 -- 102 points higher than his combined average in his first two college seasons, and he had more extra-base hits (31) than strikeouts (28).
The 6-foot-4, 230-pound Gillaspie said he improved as a hitter this season because a strong summer in the Cape Cod League helped him realize that he didn't have to try to hit homers. Using wood bats, he hit .321 and led the premier college summer league with eight long balls. He praised first-year Shockers hitting coach Brian Walker with helping him to mature at the plate.
Gillaspie also gave a great deal of the credit to his father and brother.
"I started switch-hitting when I was 9 years old," he said. "My dad taught me how to do it, and he said it would really work out for me. Of course, at times as a young kid I wanted to quit because I was struggling, but I trusted in the process and stuck with it. My dad taught me everything about hitting.
"My brother taught me about the mental side of the game. Enjoy the moment, enjoy the guys you're playing with. I learned so much from both of them. I'm blessed to have to both of them in my life, and I'm still learning from them today."
A natural right-handed hitter, Gillaspie has a similar swing from both sides of the plate. It's quick and features loft, which combined with his natural strength gives him plenty of power to all fields. Though he lacks quickness, Gillaspie has good instincts on the bases and has worked diligently to improve defensively at first base.
Compared to his brother, Casey is more streaky at the plate, though he was more consistent with his discipline and approach as a junior than he was in his first two seasons. Conor is a bit more of a pure hitter, though Casey has superior power.
The biggest difference in the two is their demeanor. Conor is known for his relentless intensity, while Casey manages to be outgoing without losing his competitive edge. Without fail, scouts mention the contrast in personalities, as do the brothers themselves.
"No doubt," Casey said with a laugh. "We'll both tell you he's more intense. I go out there and have fun. If you get to first base, I'll talk to you. I enjoy all of my time in this awesome game."
It's about to get more awesome for Gillaspie when he gets picked on the first day of the Draft on Thursday, three years after going unselected coming out of Omaha's Millard North High. He arrived at Wichita State with far less fanfare than he'll leave with.
Kemnitz's recruiting contacts -- and Conor, of course -- tipped him off about Casey, whom he remembers seeing for the first time in an American Legion tournament in the summer of 2010.
"He came up here and played in a tournament, and each game he grew on you," Kemnitz said. "Our contacts said the ball comes off his bat a little differently and he may be better than Conor, and he did look special. I didn't think he'd be a future first-rounder back then, but we were excited to sign him that November.
"Conor got us to see him and bear down on him, but Casey's talent separated him. He had a good freshman year, and each year he made a jump. This year, he made the biggest jump of all -- mentally and physically."
Looking back, Gillaspie said he always thought he was good enough to get drafted out of Millard North, but attending Wichita State made more sense than turning pro at age 18.
"It was a lot better for me -- not just for baseball, but also I've gotten tougher mentally," Gillaspie said. "I needed to mature and live on my own before I started the next part of my life. I've learned a lot about hitting and gotten my education. It's all worked out very well."
So well, in fact, that he could get picked higher than any college first baseman since Yonder Alonso went seventh overall to the Reds in 2008. One area scout likened Gillaspie to a pair of switch-hitting college first basemen who have combined to make eight All-Star Game appearances and smash 716 big league homers.
"He really knows his swing," the scout said. "He has a great approach and great strike-zone discipline. He competes, never takes an at-bat off. He's a little better left-handed, but both sides are good.
"He's a good hitter with power. He's one of the better switch-hitters I've seen in a while. I saw Mark Teixeira and Lance Berkman in college, and he has a chance to be as good as they are."
And better than the other talented members of his baseball family.
The 2014 Draft will take place on Thursday through Saturday, beginning with the Draft preview show on MLB.com and MLB Network on Thursday at 6 p.m. ET. Live Draft coverage from MLB Network's Studio 42 begins at 7 p.m., with the top 74 picks being streamed on MLB.com and broadcast on MLB Network. MLB.com's exclusive coverage of the second and third days will begin with a live Draft show at 12:30 p.m. ET on Friday.
MLB.com's coverage includes Draft Central, the Top 200 Draft Prospects list and Draft Tracker, a live interactive application that includes a searchable database of Draft-eligible players. Every selection will be tweeted live from @MLBDraftTracker, and you can also keep up to date by following @MLBDraft. And get into the Draft conversation by tagging your tweets with #mlbdraft.