Gregor hit .308 with three homers and 48 RBIs and a .440 on-base percentage for the Commodores this year, starting 65 games. He becomes the 14th of Houston's 50 Draft picks to sign. Contract terms weren't disclosed, but the 107th overall pick has a prescribed slot bonus of $481,900.
Earlier Thursday, the Astros announced the signing of nine other Draft picks, including Tony Kemp, who was Gregor's former teammate at Vanderbilt.
The other announced signings Thursday were: center fielder Jason Martin (eighth round), shortstop Thomas Lindauer (23rd), left-hander Albert Minnis (25th), right-hander William Chrismon (26th), right-hander Pat Christensen (27th), left-hander Randall Fant (29th), right-hander Zachary Morton (32nd) and right-hander Tyler Brunnemann (40th).
Kemp was the Southeastern Conference Player of the Year after an exceptional season at Vanderbilt. The 21-year-old becomes the highest Astros selection to sign thus far.
At 5-foot-7, 165 pounds, Kemp, who has drawn comparisons to Jose Altuve, led the SEC with a .391 batting average and 34 stolen bases in 48 attempts on his way to All-American honors.
"Tony has been the spark atop the Vanderbilt lineup the past few years, and we are thrilled to add him to the Astros organization," said Astros director of amateur scouting Mike Elias. "He has been a success everywhere he has played and brings energy, game-changing speed and defensive versatility to the field every day. He has excited our scouts all year, and we expect Astros fans will feel the same when they see him play."
Martin is the first high school player to sign with Houston. The 17-year-old outfielder was a third-team Rawlings All-American at Orange (Calif.) Lutheran High School.
"Jason has what we call a 'strong profile' for a center fielder. He's fast, he's a left-handed hitter, he works good at-bats and he can hit -- all ingredients to develop into a prototypical leadoff man one day," Elias said. "He impressed our scouting staff this spring with his consistent and energetic play and is only 17 years old, so we are looking forward to watching him grow and advance in our system."
The Astros have yet to come to an agreement with No. 1 overall selection Mark Appel.